Solution to question 1 continued
Solution (without a Calculator)
Method 3
| 10% of $420 |
= $42 |
| So 5% of $420 |
= $21 |
| $420 − ($42 + $21) |
= $420 − $63 |
|
= $357. |
Method 4
| 15% of $100 |
= $15 |
|
| 15% of $20 |
= $3 |
(Divide $15 by 5.) |
| 15% of $400 |
= $60 |
(Multiply $15 by 4.) |
| $420 − ($3 + $60) |
= $357. |
|
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