Question

There are blue, yellow and green tokens in a box. The ratio of the number of blue tokens to the number of yellow tokens is 2:3. The ratio of the number yellow tokens to the number of green tokens is 1:5. What is the ratio of the number of blue tokens to the total number of tokens?

Answer 1

B:y=2:3
y:g=1:5

we know that y=y so make the units same
in the b:y, y=3 units
in the y:g, y=1 units

so times the second equaton by 3 to get

b:y=2:3 and
y:g=3:15

so
b:y:g=2:3:15


now find teh ratio of blue to ttotal

total=b+y+g=2+3+15=20
blue=2
2 to total=2:20 or 1:10