The number of $10, $20 and $50 notes in a piggy bank is in the ratio of 7 : 1 : 3. The notes are worth $2880 altogether. Find the total number of $10 and $20 notes.
| |
$10 |
$20 |
$50 |
Total |
| Number |
7 u |
1 u |
3 u |
|
| Value |
$10 |
$20 |
$50 |
|
| Total value |
70 u |
20 u |
150 u |
$2880 |
Total value of $10, $20 and $50 notes
= 70 u + 20 u + 150 u
= 240 u
240 u = 2880
1 u = 2880 ÷ 240 = 12
Number of $10 and $20 notes
= 7 u + 1 u
= 8 u
= 8 x 12
= 96
Answer(s): 96
