Other — CDS Elementary Mathematics PYQs

A man starting from a place P went $x$ metre $(x>120$ m) East before turning South. He went 40 m straight before turning to West. He went 60 m to reach a place Q. From Q he went 200 m North and reached a place R. If $PR=200$ m, then what is $x$ equal to?

An amount of ₹ 10,000 is borrowed at 10% per annum on compound interest for 3 years, compounded annually, and paid back in 3 equal annual installments during these years. What is the amount of each installment (approximately)?

If the rate of interest is 5%, then what would be the difference between compound interest and simple interest received on ₹ 10,000 (each) after 3 years from now?

$A$, $B$, $C$, $D$ can complete a work in 3, 6, 9, 12 hours respectively. Further, only one person can work at a time in each hour and nobody can work for two consecutive hours. It is not necessary to engage all. What is the minimum number of hours that they will take to finish the work?

50 men can complete a work in 40 days. They begin the work together but a batch of 5 men left after each period of 10 days. What is the time to complete the work?

A sum of money invested at simple interest triples itself in 8 years and becomes $n$ times in 20 years. What is the value of $n$?

If the work done by $x$ men in $(x+1)$ days is equal to the work done by $(x+5)$ men in $(x-2)$ days, then what is the value of $x$?

Let $x$ be the compound interest at the end of 3 years on a sum of ₹ 1000 at the rate of 10% compounded annually and $y$ be the simple interest at the end of 3 years on a sum of ₹ 1000 at the annual rate of 11%. What is the difference between $x$ and $y$?

$p$ number of men can finish a piece of work in $q$ days. If there are 50% more men, then the work will be finished 12 days earlier. What is the value of $q$?

A Question is given followed by two Statements I and II. Consider the Question and the Statements.

Question:
In how many days can A, B and C together finish the work?

Statement-I: A and B together can finish the work in 24 days

Statement-II: B and C together can finish the work in 36 days

Which one of the following is correct in respect of the above Question and the Statements?