Question

A slot machine takes only 20c and 50c coins and
contains a total of 43 coins altogether. If the total value of
the coins is $13.10, find the number of 20c and 50c coins
in the machine.

Answer 1

Let the no of 50c coins be x

Then the no of 10c coins will be (21 -x)

VALUE = 0.50x + 0.10(21-x) = 4.90

0.50x + 2.1 - 0.10x = 4.90

0.40x = 2.80

x = 7

ANSWER 7 (50c) coins AND 14 (10c) coins

CHECK

7 X 0.50 = 3.50
14 X0.10 = 1.40
ADD = $4.90