The ratio of pink marbles to white marbles in samaras bag is equal to 1: 5. what percent of the bag contains pink marbles

A percentage is a ratio with a comparison to 100. So if you were writing it out it would be
X:100 or X/100
Since we have
pink:white = 1:5 or 1/5 all we have to do is multiply by a number that will give us 100 in the denominator.

1/5 × 20/20 = 20/100

20/100 = .20 = 20%

The bag contains 20% pink marbles.

2.4+3.2t. you get the answer by adding the ones with variables and ones without