Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

Question 1 : After deduction 20% from a certain sum , and then 30% from remainder , there is 3500 left . Find the original sum ?

Question 2 : A coat on sale for $120 after a discount of 20 percent. The original price of coat is ?

Question 3 :Method Of Taking L.C.M Of decimal numbers ?

M.M.Zeeshan.K

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 28,889

1. Let m be the number.

After 20% deduction, the number becomes (4/5)m.

30% of Remainder = (3/10)x(4/5)m = (12/50)m = (6/25)m.

Remaining = (19/25)m.

(19/25)m=3500.

m = 4605 approximately.

Therefore, original sum is 4605 approximately.

2. Selling price after discount = $120.

Rate of discount = 20%.

Cost price = $144, Discount = $24.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

Yes after 20% deduction number become 80m\100 , then 30 % deduction from 80m\100 number become 50m\100

So 50m\100 =3500 so m = 7000

M.M.Zeeshan.K

Offline

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

Your ans is different

M.M.Zeeshan.K

Offline

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

Question 2 steps show

M.M.Zeeshan.K

Offline

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

How original price is ,120\100 *120 ?

M.M.Zeeshan.K

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 28,889

Hi Zeeshan 01,

Problem : *A coat on sale for $120 after a discount of 20 percent. The original price of coat is ?*

Made a mistake in #2. Corrected. (Thanks for correcting).

Let the original price be $100.

Discount = 20%.

Coat on sale after discount = (Original price/Discounted price) x $120 = $150.

(100/80 x 120 = 5/4 x 120 = 150)

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

1. Let m be the number.

After 20% deduction, the number becomes (4/5)m.

30% of Remainder = (3/10)x(4/5)m = (12/50)m = (6/25)m.

Remaining = (19/25)m.

(19/25)m=3500.

m = 4605 approximately.

Therefore, original sum is 4605 approximately.

But My ans Is

after 20% deduction number become 80m\100 , then 30 % deduction from 80m\100 number become 50m\100

So 50m\100 =3500 so m = 7000

M.M.Zeeshan.K

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 28,889

Hi,

I have provided a detailed solution to how I get m = 4605 approximately. (Refer #2 and #8 above).

*Let m be the number.After 20% deduction, the number becomes (4/5)m.*

Both you and me agree in this part of the solution.

*30% of Remainder = (3/10)x(4/5)m = (12/50)m = (6/25)m.Remaining = (19/25)m.(19/25)m=3500.m = 4605 approximately.* is my interpretation.

*after 20% deduction number become 80m\100 , then 30 % deduction from 80m\100 number become 50m\100 So 50m\100 =3500 so m = 7000* is your solution.

In a way, what you have stated is true, in a way.

The problem has been posted by you.

I concede, your solution is interpreted in a different manner from my solution.

Since you posted the problem, your solution is acceptable.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Zeeshan 01****Member**- Registered: 2016-07-22
- Posts: 740

Question 3 .......

M.M.Zeeshan.K

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 28,889

Hi,

Illustration:

LCM of 0.24, 1.2 and 1.92

To find LCM of decimals, we must change the smallest number into whole number by multiplying it by any friendly number i.e. 10, 100, 1000, 10000 etc.

So, we will multiply 0.24 by 100 to make it a whole number (24).

Here, we have multiplied the smallest number by 100 so, the other two numbers will also be multiplied by hundred. Thus, we will get 24, 120 and 192.

Now, we will take LCM of all three numbers. We will get 960.

As, we had multiplied the numbers by 100, so now we will divide the obtained LCM by hundred.

So, we will get 9.6 which is our answer.

*Another Method:*

*Its just like finding the LCM of 24, 120 and 192*.

.

So it would be

.Now, you just move the decimal place back two places.

Required answer : 9.6!

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline