Question

2/3 of the beads in a box are red 1/4 are yellow and the rest are blue. There are 42 more red beads than blue beads. How many beads are there altogether?

Answer 1

The fraction of blue beads is 1 - 2/3 - 1/4 = 1/12 

If the total number of beads is t then 
red - blue = 42 
2t/3 - t/12 = 42 
therefore 
7t/12 = 42 
therefore 
t = 12x42/7 = 72