In a motor of $120$ machine parts,$5 \%$ parts were defective. In another motor of $80$ machine parts,$10 \%$ parts were defective. For the two motors considered together,the percentage of defective machine parts was (in $\%$)

$5 \%$ of $(25 \%$ of $₹ 1600)$ is

If the length of a rectangle is increased by $20 \%$ and its breadth is decreased by $10 \%$,what will be the impact on its perimeter?

An empty fuel tank of a car was filled with $A$ type petrol. When the tank was half-empty,it was filled with $B$ type petrol. Again when the tank was half-empty,it was filled with $A$ type petrol. When the tank was half-empty again,it was filled with $B$-type petrol. What is the percentage of $A$ type petrol at present in the tank?

$0.01$ is what percent of $0.1$?

What percent of Rs. $2650$ is Rs. $1987.50$?