Question

lavere has sixty-one coins, all of which are dimes and quaters. if the total value of the coins is $9.85, how many of each kind of coins has she?

Answer 1

Let the two numbers of coins be D and Q.
Solve this pair of equations:
D + Q = 61
10D + 25Q = 985 (total number of cents)
10D + 10 Q = 610
15 Q = 375
Q = ?
Take it from there

Answer 2

Q=25