The number of $2, $5 and $10 notes in a piggy bank is in the ratio of 3 : 9 : 4. The notes are worth $637 altogether. Find the total number of $2 and $5 notes.
| |
$2 |
$5 |
$10 |
Total |
| Number |
3 u |
9 u |
4 u |
|
| Value |
$2 |
$5 |
$10 |
|
| Total value |
6 u |
45 u |
40 u |
$637 |
Total value of $2, $5 and $10 notes
= 6 u + 45 u + 40 u
= 91 u
91 u = 637
1 u = 637 ÷ 91 = 7
Number of $2 and $5 notes
= 3 u + 9 u
= 12 u
= 12 x 7
= 84
Answer(s): 84
