Question 189508
The number of Peggy's 20 cents coins is 4 times that of her $5 coins. If the total amount of these coins is $17.40, how many 20 cents coins does she have?

5 cent coins = 0.05x

20 cent coins = 4(0.05x)

0.05x + 4(0.05x) = 17.50

Can you finish now?