The number of $5, $20 and $50 notes in a piggy bank is in the ratio of 8 : 5 : 7. The notes are worth $4900 altogether. Find the total number of $20 and $50 notes.
| |
$5 |
$20 |
$50 |
Total |
| Number |
8 u |
5 u |
7 u |
|
| Value |
$5 |
$20 |
$50 |
|
| Total value |
40 u |
100 u |
350 u |
$4900 |
Total value of $5, $20 and $50 notes
= 40 u + 100 u + 350 u
= 490 u
490 u = 4900
1 u = 4900 ÷ 490 = 10
Number of $20 and $50 notes
= 5 u + 7 u
= 12 u
= 12 x 10
= 120
Answer(s): 120
