Question

The ratio of pink marbles to white marbles in samaras bag is equal to 1:5. If there are 100 white marbles, how many are pink?

Answer 1

First you would add a equation to match the problem. The equation would be 100/5 and the answer would be 20. 

Answer 2

so p:w =1:5

since there are 6 units (1+5)
and 100=5 units

we want to find 1 unit so 
100/5=20
20=1unit=pink marbles