The number of $10, $20 and $50 notes in a piggy bank is in the ratio of 2 : 7 : 2. The notes are worth $1820 altogether. Find the total number of $10 and $20 notes.
| |
$10 |
$20 |
$50 |
Total |
| Number |
2 u |
7 u |
2 u |
|
| Value |
$10 |
$20 |
$50 |
|
| Total value |
20 u |
140 u |
100 u |
$1820 |
Total value of $10, $20 and $50 notes
= 20 u + 140 u + 100 u
= 260 u
260 u = 1820
1 u = 1820 ÷ 260 = 7
Number of $10 and $20 notes
= 2 u + 7 u
= 9 u
= 9 x 7
= 63
Answer(s): 63
