Carl has quarters and dimes that is worth at most $15. There are twice as many dimes as quarters. What is the greatest number of dimes that she can have?

Answer 1

D=2Q

10D+25Q < 1500

divide by 5

2D +5Q < 300

IF she had zero quarters she'd have 2D < 300 or D < 150 dimes

at most she has 150 dimes

UNLESS you interpret the problem as requiring that she has at least one quarter

the at most she has 295/2 = 147.5 dimes, but you have to have whole numbers so at most 147 dimes

OR, if you interpret the problems as having "dimes and quarterS" pliural, then she has at least 2 quarters and at most 290/2 = 145 dimes