The number of $2, $5 and $10 notes in a piggy bank is in the ratio of 4 : 3 : 9. The notes are worth $678 altogether. Find the total number of $2 and $5 notes.
| |
$2 |
$5 |
$10 |
Total |
| Number |
4 u |
3 u |
9 u |
|
| Value |
$2 |
$5 |
$10 |
|
| Total value |
8 u |
15 u |
90 u |
$678 |
Total value of $2, $5 and $10 notes
= 8 u + 15 u + 90 u
= 113 u
113 u = 678
1 u = 678 ÷ 113 = 6
Number of $2 and $5 notes
= 4 u + 3 u
= 7 u
= 7 x 6
= 42
Answer(s): 42
