Question

A stack of nickels and dimes is worth $2.55. find the number of nickels if the number of dimes is 12 less than twice the number of nickels.

Answer 1

Let # of nickels = x
So # of dimes = 2x -12, (12 less than twice the # of nickels)
Also when added their total value is $2.55. To show,
0.05(x) + 0.10(2x - 12) = $2.55 -------------- eqn1
continuing,
0.05x+0.2x-1.2=2.55
0.25x = 3.75
x= 15 ------ This is your # of nickels.
In doubt? well just go back eqn1 & substitute x=15, and you get $2.55
2. Let carol's age = x
So, Rauls'age = 2x+5
Adding the their ages will total to 101 years.