Problema Solution
A collection of 40 dimes and nickels is worth $2.90. How many nickels are there? (Hint: In your equation, use 290c instead of $2.90)
Answer provided by our tutors
number of dimes = x and nickels = y
So, => 10x+5y=290.
also, x+y = 40.
Substitute for x = 40-y in the first equation:
10(40 -y) + 5y = 290.
=> 400 -10y+5y = 290.
=> 5y = 110.
=> y = 110/5 = 22.
22 nickels are there.