PSLE Ian had a total of 100 coins in his coin box.
35 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 |
3x2 6 u |
2x2 4 u |
5x2 10 u
|
Comparison between the number of one-dollar and ten-cent coins |
2x3 |
1x3 |
|
|
Number |
6 u |
3 u |
1 u |
10 u |
Value |
1 |
0.1 |
0.5 |
|
Number x value |
6 u |
0.3 u |
0.5 u |
6.8 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 3 and 2 = 6
Total number of coins = 10 u
10 u = 100
1 u = 100 ÷ 10 = 10
Total value of coins
= 6 u 0.3 u 0.5 u
= 6.8 u
= 6.8 x 10
= $68
Answer(s): $68