A collection of 20 coins, each with a face value of either 10 cents or 35 cents, has a total face value of $2.5. How many of the coins have a face value of 10 cents?
Choose the correct choice from the following answers
A) 24
B) 18
C) 32
D) 16
E) 20
0.10(x)+0.35(20-x)=2.5   0.10x+7-0.35x=2.5   so x=18   ans is 18
<result>B</result>
A collection of 20 coins, each with a face value of either 10 cents or 35 cents, has a total face value of $2.5. How many of the coins have a face value of 10 cents?