The number of $10, $20 and $100 notes in a piggy bank is in the ratio of 9 : 8 : 4. The notes are worth $6500 altogether. Find the total number of $20 and $100 notes.
| |
$10 |
$20 |
$100 |
Total |
| Number |
9 u |
8 u |
4 u |
|
| Value |
$10 |
$20 |
$100 |
|
| Total value |
90 u |
160 u |
400 u |
$6500 |
Total value of $10, $20 and $100 notes
= 90 u + 160 u + 400 u
= 650 u
650 u = 6500
1 u = 6500 ÷ 650 = 10
Number of $20 and $100 notes
= 8 u + 4 u
= 12 u
= 12 x 10
= 120
Answer(s): 120
