Oscar has 20-cent coins and 50-cent coins. The total value of all his coins is $37. He has 4 less 20-cent coins than 50-cent coins. How many coins does he have altogether?
|
20-cent |
50-cent |
Total |
Number |
1 u |
1 u + 4 |
2 u + 4 |
Value |
20 |
50 |
|
Total value |
20 u |
50 u + 200 |
70 u + 200 |
$1 = 100¢
$37 = 37 x 100 = 3700¢
Oscar has 4 more 50-cent coins than 20-cent coins.
Number of 20-cent coins = 1 u
Number of 50-cent coins = 1 u + 4
Total value of 20-cent coins
= 20 x 1 u
= 20 u
Total value of 50-cent coins
= 50 x (1 u + 4)
= 50 u + 200
Total value of the coins
= 20 u + 50 u + 200
= 70 u + 200
70 u + 200 = 3700
70 u = 3700 - 200
70 u = 3500
1 u = 3500 ÷ 70 = 50
Total number of coins
= 1 u + (1 u + 4)
= 2 u + 4
= 2 x 50 + 4
= 100 + 4
= 104
Answer(s): 104