NCERT Solutions for Chapter: Comparing Quantities, Exercise 1: Exercise

In how many years will a certain sum becomes five times itself at $20\%$ per annum simple interest.

The income of a person A increases from $₹12,000$ to $₹14,000$ and the expenditure increases from $40\%$ to $50\%$. Find the percentage increase or decrease in the monthly savings of A.

In an office, one day, $20\%$ of the staff members were on leave in the morning session. On that same day, $10\%$ of the staff, who were on leave, came for the afternoon session. If total strength of the office is $400$, then how many were present for the evening session? (The persons who were present in the morning session were also present in the afternoon session).

The ratio of the incomes of $P$ and $Q$ is $5:4$. The ratio of their expenditure is $4:3$. The savings of $P$ is more than that of $Q$ by $16\frac{2}{3}\%$. What percentage of his income does $P$ spend?

In school $X$, the number of boys is more than that of girls by $40\%$. In school $Y$, the number of girls is more than that of boys by $50\%$. If $50\%$ boys in school $X$ is equal to $70\%$ of girls in school $Y$, what is the ratio between the number of students of school $X$ and school $Y$?

The price of an article increased successively over three consecutive weeks. It increased by $10\%$ in the $1^{\mathrm{st}}$ week, $20\%$ in the $2^{\mathrm{nd}}$ week and $25\%$ in the $3^{\mathrm{rd}}$ week. Find the effective percentage increase in its price after three weeks.

In what time will $₹8000$ amount to $₹8360$ at $6\%$ per annum simple interest?

A sum doubles itself at simple interest at $10\%$ per annum in $10$ years.