PSLE Jack had a total of 240 coins in his coin box.
112 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 |
1x2 2 u |
11x2 22 u |
12x2 24 u
|
Comparison between the number of one-dollar and ten-cent coins |
2x1 |
1x1 |
|
|
Number |
2 u |
1 u |
21 u |
24 u |
Value |
1 |
0.1 |
0.5 |
|
Number x value |
2 u |
0.1 u |
10.5 u |
12.6 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 1 and 2 = 2
Total number of coins = 24 u
24 u = 240
1 u = 240 ÷ 24 = 10
Total value of coins
= 2 u 0.1 u 10.5 u
= 12.6 u
= 12.6 x 10
= $126
Answer(s): $126