Question

CHRIS HAS A JAR WITH 34 COINS. THERE ARE ONLY NICKELS AND QUARTERS IN THEH JAR. CHRIS COUNTS THE MONEY AND HE HAS $3.90. HOW MANY QUARTERS ARE IN THE JAR?

Answer 1

Let number of nickels and quarters be x and y respectively.

given,

x + y = 34 --------------------(1)

and x/20 + y/4 = 3.9  ------------(2)

from (1) we get:

x = 34 - y --------------------------(3)

putting the value of x from (3) into (2) we get:

(34-y)/20 + y/4 = 3.9

on multiplying both side by 20 we get:

20(34-y)/20 + 20y/4 = 20*3.9

or 34 - y + 5y = 78

or 34 + 4y = 78

or 4y = 78 -34

or 4y = 44

or y =11

So there are 11 quarters in the jar.