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A number is increased by 20% and then again by 20%. By what per cent should the increased number be reduced so as to get back the original number ?
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30 5 % 9 -
19 11 % 31 - 40%
- 44%
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Correct Option: A
Let the number be 100.
After 20% increase, number = 120
After 20% increase of 120, number
| = 120 × | = 144 | 100 |
∴ Per cent decrease
| = | × 100 | 144 |
| = | = 30 | % | ||
| 9 | 9 |
Aliter : Using Rule 7 and Rule 8,
Increase %
| = |  | 20 + 20 + |  | % = 44% | |
| 100 |
Required %
| = | | | × 100% | |
| 100 + 44 |
| = | % | 144 |
| = | % = 30 | % | ||
| 9 | 9 |
