Question

Bob has $150 in his savings account and saves $40 a month. Andrea has only $100 in her account but saves at a rate of $50 a month. When will Andrea have saved more than Bob?

Answer 1

x = number of months
Bob = 150 + 40x
Andrea = 100 + 50x

100 + 50x > 150 + 40x
50x > 50 + 40x
10x > 50
x > 5

So starting month 6, Andrea will have saved more than Bob.