Question 1128491: Isabelle paid for her $1.75 lunch with 87 coins. If all the coins were nickels and pennies , how many were there of each type of coin Answer by greenestamps(13200) (Show Source):
let n = number of nickels
then (87-n) = number of pennies
The total value of the coins (5 cents for each nickel and 1 cent for each penny) was $1.75 = 175 cents. Write and solve the equation that says that:
You can finish the formal solution.
Informally, using logical reasoning....
(1) If all 87 coins were pennies, that would be only 87 cents; the actual total of 175 cents is 175-87 = 88 cents more than that.
(2) Exchanging a penny for a nickel keeps the same total of 87 coins but increases the total value by 4 cents.
(3) To make up those other 88 cents, the number of nickels needed is 88/4 = 22.
