PSLE Vaidev had a total of 45 coins in his coin box.
49 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 twenty-cent coins. What was the total value of all the coins in his coin box?
|
One-dollar |
Ten-cent |
Twenty-cent |
Total |
Comparison between the number of 3 types of coins |
4x1 4 u |
5x1 5 u |
9x1 9 u
|
Comparison between the number of one-dollar and ten-cent coins |
2x2 |
1x2 |
|
|
Number |
4 u |
2 u |
3 u |
9 u |
Value |
1 |
0.1 |
0.2 |
|
Number x value |
4 u |
0.2 u |
0.6 u |
4.8 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 4 and 2 = 4
Total number of coins = 9 u
9 u = 45
1 u = 45 ÷ 9 = 5
Total value of coins
= 4 u 0.2 u 0.6 u
= 4.8 u
= 4.8 x 5
= $24
Answer(s): $24