If the radius of a cylinder is decreased by 50 % and the

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If the radius of a cylinder is decreased by 50 % and the height is increased by 50 %, then the change in volume is

1. 52.5 %
2. 67.5 %
3. 57.5 %
4. 62.5 %

Correct Option: D

Using Rule 10,
Single equivalent decrease for 50% and 50%

=		50 - 50 +	50 × 50		% = ( - 100 + 25) % = - 75%
			100

Single equivalent percent for – 75% and 50%

=		- 75 + 50 -	75 × 50		% = ( - 25 - 37.5) % = - 62.5%
			100

Negative sign shows decrease.