$0.06 \%$ of $250 \%$ of $1600$ is

Peter could save $10 \%$ of his income. But two years later,when his income increased by $20 \%$,he could save the same amount as before. By what percentage has his expenditure increased?

$x \%$ of $y + ? \%$ of $x = x \%$ of $(x + y)$

The quantity of water needed to reduce $9 \ ml$ of shaving lotion containing $50 \%$ alcohol to a lotion containing $30 \%$ alcohol is: (in $ml$)

In an election between two candidates,one got $55 \%$ of the total valid votes,and $20 \%$ of the total votes were invalid. If the total number of votes was $7500$,what was the number of valid votes that the other candidate received?

Two-fifths of one-third of three-seventh of a number is $15$. What is $40$ per cent of that number?