Question

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

Answer 1

Total = 12x42/7 = 72

Answer 2

r = number of red
b = number of blue
y = number of yellow
r = b + 42 or b = r - 42 and I suppose r - b = 42
Fraction that are blue
1 - ( 2/3 + 1/4 )
1 - ( 8/12 + 3/12 )
1 - ( 11/12 )
b = 1/12
Since y is 1/4 and y = 3/12, y = 3b

Since r is 2/3 and r = 8/12, r = 8b
Combine r = b + 42 with r = 8b
This means that b + 42 = 8b
Subtract b from each side
42 = 7b
6 = b
So we have b = 6 , y = 3b and r = 8b
Since b + y + r = total
By substituting
6 + 3(6) + 8(6) = total
6 + 18 + 48 = 72