Question

A jar contains 10 red marbles and 30 green ones. H ow many red marbles must be added to the jar so that 60% of the marbles will be red?
a) 25
b) 30
c) 35
d) 40

Answer 1

red 10
green 30
total 40
60% of 40=24
24-10=14
14 red balls have to be added to make it 60%