Fraction Word Problem

Question

3500kg of Sand was bought. 1/2 was used on a building project, 1/5 on a fish pond and 1/8 on a splash pool. How much of the sand is left? 

Answer 1

Convert all fractions to a common denominator.

1/8 = 5/40

1/5 = 8/40

1/2 = 20/40

Add them up to get 33/40.  This is the fraction of sand used.  The fraction of sand remaining will be 40/40 - 33/40 = 7/40.

Then, 7/40 x 3500 kg = 612.5 kg