PSLE Liam had a total of 360 coins in his coin box.
79 of all the coins saved were one-dollar coins. There were 4 times as many one-dollar coins as twenty-cent coins. The remaining coins were ten-cent coins. What was the total value of all the coins in his coin box?
|
One-dollar |
Twenty-cent |
Ten-cent |
Total |
Comparison between the number of 3 types of coins |
7x4 28 u |
2x4 8 u |
9x4 36 u
|
Comparison between the number of one-dollar and twenty-cent coins |
4x7 |
1x7 |
|
|
Number |
28 u |
7 u |
1 u |
36 u |
Value |
1 |
0.2 |
0.1 |
|
Number x value |
28 u |
1.4 u |
0.1 u |
29.5 u |
Number of $1 coins is the repeated identity.
Make the number of $1 coins the same.
LCM of 7 and 4 = 28
Total number of coins = 36 u
36 u = 360
1 u = 360 ÷ 36 = 10
Total value of coins
= 28 u 1.4 u 0.1 u
= 29.5 u
= 29.5 x 10
= $295
Answer(s): $295