Trouble multiplying 3 or more simple fractions?

Question

Okay, I'm not sure I'm getting this...
Take this problem for example:6/10 x 45/18 x 15/48
Okay this is what I do, I factor them down 3x2 9x5 5x3 for the numerators, and 5x2 9x2 and 24x2 for the denominators, and I end up doing 3x3 = 9 and 2x2=4+24=28 and I said 9/28 when the answer aucctly turns out to be 15/32
Wtf am I doing wrong?

Answer 1

Let's go through this step-by-step. Then maybe we can find the problem.

THE FIRST THING YOU WANT TO DO WHEN YOU MULTIPLY FRACTIONS, IS TO SIMPLIFY! Which you did, good job.

(6/10)(45/18)(15/48) -the parenthesis means multiply.

Best bet here is to simplify the BIGGEST numbers first. Simplifying numbers by 2 is usually easy to do, so try doing that... Eventually, my simplified equation got me to...

(1/2)(3/6)(15/8)

Got 45/96

Which got me to 15/32.

Dude, you get this stuff. You're right. According to my TI-83 calc, the answer is 15/32, it should be right man. xD Enjoy your day.

Answer 2

Doing that one in a straight line is a nigh mare!
Lets try something a bit easier to in a text-box so you get the idea
Lets do part of the one you had:
6/10 x 15/48
We look for factors on the top that are also on the bottom
5 goes into 10 on the bottom of 6/10 and into 15 on the top of 15/48
So cancel
So it becomes 6/2 x 3/48
6 goes into 6 on the top of 6/2 and into 48 on the bottom of 3/48
So cancel and it becomes 1/2 x 3/8
There is no more we can do, so x the top numbers (1 x 3 = 3)
x the bottom numbers (2 x 8 = 16)
and you have 3/16
I hope this has not confused you any more and may have even thrown a bit of light on the problem!

Answer 3

Why not?

6X45X15 / 10X18X48

4050 / 8640

Canceling the 0s (dividing by 10)
405 / 864

Divide both Numerator and Denominator by 27 resulting in:

15/32

I think you just got too complicated in the factoring. One place I see you wrote 2X2=4+24=28. Why the plus? I thought all factoring was multiplication.

Anyway, with a calculator, big numbers are easier to deal with than when I was in school in the 50s and 60s. No need to complicate it.

Answer 4

Reduce by eliminating whatever is equal from the numerator and denominator. So with the numbers you gave, your fraction becomes(3x5x3)/ (2x24x2). So the answer is 45/96 not 9/28. Using the same approach you had initially, 45/96 can be reduced further. (3x3x5)/(3x4x8) = 15/32.

Answer 5

Try just multiplying the numerators, then multiply the denominators, then reduce the answer to simlest form

6/10 x 45/18 x 15/48

(6x45x15)/(10x18x48) = 4050/8640
4050/8640 divide both numerator and denominator by 270
15/32

Answer 6

I dont understand what you are doing. In any way it should be 15/32. Why you are adding? please expalain how you ended with 3X3. You should have ended with 3X3X5 for numerator. and 2X2X24 for denomintor. Dont add 2X2 to 24 but multiply. Further deviding you will get the answer.

Answer 7

Simplify each fraction
6/10=3/5
45/18=5/2
15/48=5/16
Multiply them, simplify, and you get 15/32