PSLE Seth had a total of 200 coins in his coin box.
710 of all the coins saved were one-dollar coins. There were 4 times as many one-dollar coins as fifty-cent coins. The remaining coins were ten-cent coins. What was the total value of all the coins in his coin box?
|
One-dollar |
Fifty-cent |
Ten-cent |
Total |
Comparison between the number of 3 types of coins |
7x4 28 u |
3x4 12 u |
10x4 40 u
|
Comparison between the number of one-dollar and fifty-cent coins |
4x7 |
1x7 |
|
|
Number |
28 u |
7 u |
5 u |
40 u |
Value |
1 |
0.5 |
0.1 |
|
Number x value |
28 u |
3.5 u |
0.5 u |
32 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 = 40 u
40 u = 200
1 u = 200 ÷ 40 = 5
Total value of coins
= 28 u 3.5 u 0.5 u
= 32 u
= 32 x 5
= $160
Answer(s): $160