PSLE Simon saved a total of $86 in coins in his coin box.
18 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. How many coins did Simon save in his coin box altogether?
|
One-dollar |
Ten-cent |
Fifty-cent |
Total |
Comparison between the number of 3 types of coins |
1x2 2 u |
7x2 14 u |
8x2 16 u
|
Comparison between the number of one-dollar and ten-cent coins |
2x1 |
1x1 |
|
|
Number |
2 u |
1 u |
13 u |
16 u |
Value |
1 |
0.1 |
0.5 |
|
Number x value |
2 u |
0.1 u |
6.5 u |
8.6 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 1 and 2 = 2
Total value of coins = 8.6 u
8.6 u = 86
1 u = 86 ÷ 8.6 = 10
Total number of coins
= 2 u + 1 u + 13 u
= 16 u
= 16 x 10
= 160
Answer(s): 160