number of quarters --- x
number of dimes --- 21-x
25x + 10(21-x) = 345
25x + 210 - 10x = 345
15x = 135
x = 9
He has 9 quarters and 12 dimes
check:
9(25) + 12(10) = 345 , check!!
Daniel has 21 coins. All of them are either quarters or dimes. Altogether, he has $3.45. How many of each type of coin does he have?
1 answer