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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Hi all I have some questions plese help me for solving this

all this competition is going to be held and I have some questions in question paper hope you help me in solving this paper ...#SEE BELOW and give logic

Question 1

At National School, 50% of the students have bicycles. Of the students who have bicycles, 30% have black bicycles. What percent of students of National School have black bicycles ? (A) 15% (B) 20% (C) 25% (D) 40%

QUESTION 2

To make concrete, mix 4 shovels of stone, 2 shovels of sand and 1 shovel of cement. The number of shovels of stone required to make 350 shovels of concrete is: (A) 200 (B) 150 (C) 100 (D) 50

Question 3

A group of friends is planning a trip. If each of them would make a contribution of Rs.14 for the expected travel expenses, they would be Rs.4 short. But if each of them would make a contribution of Rs.16, they would have Rs.6 more than they need. How much should each of the friends contribute so that they collect exactly the amount needed for the trip?

Question 4

The watchman works 4 days a week and has a rest on the fifth day. He had been resting on Sunday and began working on Monday. After how many days will his rest fall on Sunday? (A) 31 (B) 12 (C) 34 (D) 7

New Question 5

If the surface area of sphere is 100pi cm^2 ,it's radius will be

*Last edited by Zeeshan 01 (2017-01-17 04:47:38)*

Math !!!!.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

Question 5) Anything wrong with trying all 4 and a bit of algebra.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Ok I solving question 5 plese help in other four questions

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,023

bobbym wrote:

Question 5) Anything wrong with trying all 4 and a bit of algebra.

Better try with maximum 3 digit number and minimum 2 digit number.

**{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha{Gods rejoice at those places where ladies are respected.}**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

There is also problem in question 5 can you solve this I have tried but how I find ans it's like equation show me

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

Hi;

Multiple choice questions are gifts. If you can not see any other way then try em all!

Call a the 3 digit number and call b the 2 digit number. You have the equations

a - b = 989, a + b = n

where n must be one of the 4 choices. Can you finish now?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Hmmm

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

And what ans of question 5

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

How I know eq a-b=989 and a -b= n how I find n

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

Question 5

Mike chose a three-digit number and a two-digit number. Find the sum of these numbers if their difference equals 989. (A) 1000 (B) 1001 (C) 1009 (D) 1010

Try the first:

a - b = 989

a + b = 1000

Add the two equations:

2a = 1989

a = 1989 / 2 which is not a 3 digit number, so 1000 is out.

Can you do the rest?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Whay you equals to 1000

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

One of the 4 choices given is what a + b is.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Ok your ans is ???

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

I did not give you the answer. I gave you the simplest means of getting the answer if you have no other method. Do you agree that A) is not possible?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Ok I solve this eq ???? See

A-b=1001

A-b=1009

A-b=1010

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

No, you solve both equations for each one.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

First I do eq minus of add and subtract then 2a comes and divide options with 2 ?????

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

Since you did not answer the question

bobbym wrote:

Do you agree that A) is not possible?

Let us go over the first one again:

a - b = 989

a + b = 1000

Have you learned how to solve 2 simultaneous equations yet?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Adding both eqs 2a=1989

994.5

Math !!!!.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

The problem states that he picked a 3 digit number and a 2 digit number. We called the 3 digit number a and we solved for it. We got a = 994.5 which is not a 3 digit number, so A)1000 is out.

If you understand this then move on to B).

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Oohh ?????? 1010 is not real ans because 1010 divide by 2 eq 505??

Math !!!!.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

B) 1001

a - b = 989

a + b = 1001

2a =1990

So a = 995 and b = 6. The problem says he picked a 3 digit number and 995 is a 3 digit number but 6 for b is not a 2 digit number. So B) 1001 is out.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Got the àns of question 5 1009

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 107,764

That is the correct answer for the old question #5 but since you did not show any work I can not say anything else about it.

I had this conversation with a very clever fellow:

bobbym: I was not able to go throught that book on order statistics and get much out of it. I solved the problem though.

clever dude: I also could not understand that book all filled with silly symbols. I thought about it and solved it like this.

I am willing to let someone skip the theoretical jargon, do we really need to memorize yet another proof from Cauchy? I am much more alarmed when someone skips over the problems assigned to him/her. Also, a competition is a sporting event. By that we can infer that you are supposed to be doing these problems on your own. I am not in the competition, it is unfair for you to receive the answers. I am willing to help as is everyone else in here but you have to show some work, some effort, some something.

This problem #6 is real easy

Question 6

In triangle abc the angle a is three times the size of that at b and half the size of the angle at c. what is the angle at A???

A 30 b 36 degree c 54 deg d 60 degree

and again it is a multiple choice. It is also carelessly written, first you talk about angle a and then later it becomes angle at A? In math a and A are not the same things. Now, how about trying some things and showing your work?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 333

Angle a is a

Angle b is b

Angle c is c

According to statement angle a is three time means 3a

How I think of question 3 times than of b what is mean of this line???

Math !!!!.

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