Piggy bank problem

Question

$5.40 in piggy bank. Five more dimes than quarters, seven more nickels than dimes and three times as many pennies as quarters how many of each do I have

Answer 1

D = Q+5

N = D+7 = Q+5+7 = Q+12

P = 3Q

25Q+ 10(Q+5) + 5(Q+12)+3Q = 540 <--- amount in pennies

25Q + 10Q + 50 + 5Q + 60 + 3Q = 540

43Q + 110 = 540

43Q = 430

Q = 10

10 quarters

15 dimes

22 nickles

30 pennies

That's $2.50 + $1.50 + 1.10 + 0.30 = 5.40