Julian has 10-cent coins and 50-cent coins. The total value of all his coins is $25. He has 20 less 10-cent coins than 50-cent coins. How many coins does he have altogether?
| |
10-cent |
50-cent |
Total |
| Number |
1 u |
1 u + 20 |
2 u + 20 |
| Value |
10 |
50 |
|
| Total value |
10 u |
50 u + 1000 |
60 u + 1000 |
$1 = 100¢
$25 = 25 x 100 = 2500¢
Julian has 20 more 50-cent coins than 10-cent coins.
Number of 10-cent coins = 1 u
Number of 50-cent coins = 1 u + 20
Total value of 10-cent coins
= 10 x 1 u
= 10 u
Total value of 50-cent coins
= 50 x (1 u + 20)
= 50 u + 1000
Total value of the coins
= 10 u + 50 u + 1000
= 60 u + 1000
60 u + 1000 = 2500
60 u = 2500 - 1000
60 u = 1500
1 u = 1500 ÷ 60 = 25
Total number of coins
= 1 u + (1 u + 20)
= 2 u + 20
= 2 x 25 + 20
= 50 + 20
= 70
Answer(s): 70
