Rita invested $25 \%$ more than Sunil. Sunil invested $30 \%$ less than Abhinav who invested $Rs. 6000$. What is the respective ratio between the amount that Rita invested and the total amount invested by all of them together?

Water tax is increased by $20 \%$ but its consumption is decreased by $20 \%$. The increase or decrease in the expenditure is:

$1200$ boys and $650$ girls appeared in an examination. If $70 \%$ of boys and $40 \%$ of girls failed,find the approximate percentage of passed students.

An army lost $10 \%$ of its men in war,$10 \%$ of the remaining died due to disease,and $10 \%$ of the rest were declared disabled. Thus,the strength of the army was reduced to $7,29,000$ active men. What was the original strength of the army?

Sonu invested $10 \%$ more than Mona. Mona invested $10 \%$ less than Raghu. If the total sum of their investments is ₹$5,780$,how much amount did Raghu invest?

For admission in a postgraduate program of Calcutta University,$90 \%$ of the candidates who appeared for the written test were males and the rest were females. $60 \%$ of the males and $80 \%$ of the females passed the written test. What is the total number of students who appeared for the written test,if the total number of passed candidates was $1240$?