i have 8 coins in my piggy bank. I have twice as many dimes as I have quarters. I have twice as many pennies as I have dimes. I have less than 95 cents altogether. How many of each coin do I have?

Answer 1

Let P be the number of pennies, D be the number of dimes, Q be the number of quarters, and N the number of nickels
(if N is 0, we will discover it when we solve the system of equations)

P + D + Q + N = 8
P = 2*D
D = 2*Q
P + 10*D + 25*Q < 95

Q can only be only 1, otherwise P >= 8

So then D must be 2
and P must be 4
and then there must be one nickel