The number of $10, $20 and $100 notes in a piggy bank is in the ratio of 8 : 5 : 2. The notes are worth $1900 altogether. Find the total number of $10 and $20 notes.
| |
$10 |
$20 |
$100 |
Total |
| Number |
8 u |
5 u |
2 u |
|
| Value |
$10 |
$20 |
$100 |
|
| Total value |
80 u |
100 u |
200 u |
$1900 |
Total value of $10, $20 and $100 notes
= 80 u + 100 u + 200 u
= 380 u
380 u = 1900
1 u = 1900 ÷ 380 = 5
Number of $10 and $20 notes
= 8 u + 5 u
= 13 u
= 13 x 5
= 65
Answer(s): 65
