solution please

balasvce · 2006-12-20 18:31:19

X = 12
y = 15
xy is a multile of what??

Devantè · 2006-12-20 19:15:11

You mean multiple?

180 is a multiple of 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90 and 180.

Because 12x15 = 180.

Now tell me how I went about finding all those multiples.

Last edited by Devanté (2006-12-21 19:09:59)

mathsyperson · 2006-12-21 02:50:00

In a non-exhaustive way, by the looks of it.

To find all numbers that a number is a multiple of, you need to split it up into prime factors first.
12 = 2² x 3
15 = 3 x 5.

Therefore, 12 x 15 = 2² x 3 x 3 x 5 = 2² x 3² x 5.

Now you combine every combination of these prime factors and you will get every factor of 180.

Without x5: With x5:
x1 x2 x2² x1 x2 x2²
x1 1 2 4 5 10 20
x3 3 6 12 15 30 60
x3² 9 18 36 45 90 180

So, 180 is a multiple of 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90 and 180.

You don't have to draw out the table every time, I just did that to be ultra-clear, but if you don't then it's quite easy to accidentally miss one out.

balasvce · 2006-12-21 03:55:41

can you tell me how to solve this 1/96 + 1/97 + 1/98 + 1/99 + 1/100=?
thanx in advance

Toast · 2006-12-21 04:05:24

I guess just make all the denominators the same and simplify:

≈ 0.051031036751

Last edited by Toast (2006-12-21 04:09:40)

Stanley_Marsh · 2006-12-21 04:08:52

you can simply combine all of them together and do division .

balasvce · 2006-12-21 04:31:39

a bit more easier method

balasvce · 2006-12-21 04:33:29

10)which Of The Following Words Can You Arrange In 180

Differnt Ways
There Were 4 Options
Some Words Some Were 4 Letter Some 5 Letter Some 6 Letter

Answer Was One Of The 6 Letter Word There Were 2 Six Letter

Word
can someone give an illustration of this kind of problem
18) the series problem.. here k>=2 if ak = a (k-1) + 4.. and a1= 3.

find the 100th term
11) set A contains multiple of 6 n set b contains multiples of

8. No. of multiplies in set C which has common multiplies of A

and B.

Last edited by balasvce (2006-12-21 04:52:55)

mathsyperson · 2006-12-21 06:30:32

For the adding fraction thing, that's really the only way that you can do it. There isn't a simpler method. If you want to approximate the answer, you can say that all of the fractions are at least as big as 1/100 and that they are all at least as small as 1/96.

Therefore, the total would be between 5/100 (=1/20) and 5/96.

For your second question, it would have been a lot easier if you had given us what the words were. But it's quite likely that the answer word would have had 6 letters and two sets of 2 repeated letters. Like "letter". As you haven't given us the options, I can't tell you the exact answer.

Math Is Fun Forum

#1 2006-12-20 18:31:19

solution please

#2 2006-12-20 19:15:11

Re: solution please

#3 2006-12-21 02:50:00

Re: solution please

#4 2006-12-21 03:55:41

Re: solution please

#5 2006-12-21 04:05:24

Re: solution please

#6 2006-12-21 04:08:52

Re: solution please

#7 2006-12-21 04:31:39

Re: solution please

#8 2006-12-21 04:33:29

Re: solution please

#9 2006-12-21 06:30:32

Re: solution please

Board footer