The difference between a number and its two-fifth is $610$. What is $10\%$ of that number?

From the salary of an officer,$10\%$ is deducted as house rent,$15\%$ of the rest he spends on children's education,and $10\%$ of the balance,he spends on clothes. After this expenditure,he is left with $₹ 1377$. His salary is:

$A$ man spends $75 \%$ of his income. His income is increased by $20 \%$ and he increases his expenditure by $10 \%$. His savings are increased by: (in $\%$)

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 $\%$)

About $8 \%$ of the voters in an election did not cast their votes. In this election,there were only two candidates. The winner,by obtaining $48 \%$ of the total votes,defeated his contestant by $1100$ votes. The total number of voters in the election was:

$34.5 \% \text{ of } 1800 + 12.4 \% \text{ of } 1500 = (?)^3 + 78$