Multiply (Divide) Fractions

Question

A string 60 meters long must be cut into pieces that are 2 1/2 meters long. How many pieces of string will there be after this cut?

Answer 1

First I'm going to change 2 1/2 into an improper fraction:

2 + (1/2)  = [2*(2/2)] + (1/2) = (4/2) + (1/2) = 5/2

 

Now I just need to divide 60 m by 5/2 m:

60 / (5/2) ----> 60 * (2/5) (Remember that when dividing fractions, you just multiply by the dividing fraction's reciprocal)

60*(2/5) = 120/5 = 24

 

Therefore, 24 pieces of string need to be cut.