PSLE Ben saved a total of $73 in coins in his coin box.
49 of all the coins saved were one-dollar coins. There were 3 times as many one-dollar coins as ten-cent coins. The remaining coins were twenty-cent coins. How many coins did Ben save in his coin box altogether?
|
One-dollar |
Ten-cent |
Twenty-cent |
Total |
Comparison between the number of 3 types of coins |
4x3 12 u |
5x3 15 u |
9x3 27 u
|
Comparison between the number of one-dollar and ten-cent coins |
3x4 |
1x4 |
|
|
Number |
12 u |
4 u |
11 u |
27 u |
Value |
1 |
0.1 |
0.2 |
|
Number x value |
12 u |
0.4 u |
2.2 u |
14.6 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 4 and 3 = 12
Total value of coins = 14.6 u
14.6 u = 73
1 u = 73 ÷ 14.6 = 5
Total number of coins
= 12 u + 4 u + 11 u
= 27 u
= 27 x 5
= 135
Answer(s): 135