The population of a town increases by $2.5 \%$ annually but decreases by $0.5 \%$ every year due to migration. What will be the net percentage increase in population after $2$ years (in $\%$)?

An article is sold at a discount of $20 \%$ on the marked price. In order to gain $60 \%$ on the marked price,at how much more percent of the discounted price should it be sold?

The radius of a sphere is increased by $10 \%$. The surface area increases by

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 $\%$)

Of the $1000$ inhabitants of a town,$60 \%$ are males of whom $20 \%$ are literate. If,of all the inhabitants,$25 \%$ are literate,then what per cent of the females of the town are literate (in $.5$)?

In a test,the minimum passing percentage for girls and boys is $35 \%$ and $40 \%$ respectively. $A$ boy scored $483$ marks and failed by $117$ marks. What are the minimum passing marks for girls?