A boy has 11 coins in dimes and quarters. Their value is $1.70. How many of each does he have? Which of the following equations could be used to solve the problem? x + (11 - x) = 1.70. 25x + 10(11 - x) = 1.70. 0.10x + 0.25(11 - x) = 1.70
x - number of dimes, y - number of quarters x + y = 11 0.10 x + 0.25 y = 1.70 0.10 x + 0.25 ( 11 - x ) = 1.70 We can solve it: 0.10 x + 2.75 x - 0.25 x = 1.70 0.15 x = 1.05 x = 1.05 : 0.15 x = 7 ( a boy has 7 dimes and 4 quarters ) Answer: D ) 0.10 x + 0.25 ( 11 - x ) = 1.70
