Multiply 520 students by 20% (0.20).
520 * 0.20 = 104
Multiply 104 students by 12.5% (0.125).
104 * 0.125 = 13
13 students were on the wrestling team.
dimes (d) = n + .80, nickels (n) = n
Make the dimes and nickels add up to $1.40 in an equation.
(n + .80) + n = 1.40
Combine like terms.
2n + .80 = 1.40
Subtract .80 from both sides.
2n = 0.60
Divide both sides by 2.
n = 0.30
Divide this by 0.05 (how many nickels are in a dollar).
0.30/0.05 = 6
d = n + 0.80 ⇒ 0.30 + 0.80 = 1.10
Divide this by 0.10 (how many dimes are in a dollar).
1.10/0.10 = 11
There are 6 nickels and 11 dimes in the bank.