PSLE Jenson had a total of 108 coins in his coin box.
59 of all the coins saved were one-dollar coins. There were 2 times as many one-dollar coins as ten-cent coins. The remaining coins were fifty-cent coins. What was the total value of all the coins in his coin box?
|
One-dollar |
Ten-cent |
Fifty-cent |
Total |
Comparison between the number of 3 types of coins |
5x2 10 u |
4x2 8 u |
9x2 18 u
|
Comparison between the number of one-dollar and ten-cent coins |
2x5 |
1x5 |
|
|
Number |
10 u |
5 u |
3 u |
18 u |
Value |
1 |
0.1 |
0.5 |
|
Number x value |
10 u |
0.5 u |
1.5 u |
12 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 5 and 2 = 10
Total number of coins = 18 u
18 u = 108
1 u = 108 ÷ 18 = 6
Total value of coins
= 10 u 0.5 u 1.5 u
= 12 u
= 12 x 6
= $72
Answer(s): $72