Elijah has 20-cent coins and 50-cent coins. The total value of all his coins is $19. He has 3 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 + 3 |
2 u + 3 |
| Value |
20 |
50 |
|
| Total value |
20 u |
50 u + 150 |
70 u + 150 |
$1 = 100¢
$19 = 19 x 100 = 1900¢
Elijah has 3 more 50-cent coins than 20-cent coins.
Number of 20-cent coins = 1 u
Number of 50-cent coins = 1 u + 3
Total value of 20-cent coins
= 20 x 1 u
= 20 u
Total value of 50-cent coins
= 50 x (1 u + 3)
= 50 u + 150
Total value of the coins
= 20 u + 50 u + 150
= 70 u + 150
70 u + 150 = 1900
70 u = 1900 - 150
70 u = 1750
1 u = 1750 ÷ 70 = 25
Total number of coins
= 1 u + (1 u + 3)
= 2 u + 3
= 2 x 25 + 3
= 50 + 3
= 53
Answer(s): 53
