PSLE Oscar saved a total of $88 in coins in his coin box.
27 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 Oscar save in his coin box altogether?
|
One-dollar |
Ten-cent |
Twenty-cent |
Total |
Comparison between the number of 3 types of coins |
2x3 6 u |
5x3 15 u |
7x3 21 u
|
Comparison between the number of one-dollar and ten-cent coins |
3x2 |
1x2 |
|
|
Number |
6 u |
2 u |
13 u |
21 u |
Value |
1 |
0.1 |
0.2 |
|
Number x value |
6 u |
0.2 u |
2.6 u |
8.8 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 2 and 3 = 6
Total value of coins = 8.8 u
8.8 u = 88
1 u = 88 ÷ 8.8 = 10
Total number of coins
= 6 u + 2 u + 13 u
= 21 u
= 21 x 10
= 210
Answer(s): 210