DELHI POLICE MATHS QUIZ -13

After allowing three successive discount of 15%, 20% and 18% on the marked price of an article, it is sold for Rs. 2,230.40. The marked price (in Rs) of the article is:

A sum of ₹ 8,000 amounts to ₹ 13,824 in 3 years at $R \%$ p.a., interest compounded annually. What will it amount to in $1 \frac{1}{4}$ years at the same rate, if the interest is compounded half-yearly?

The value of $\frac{4}{5} \div \frac{3}{10}$ of $\frac{4}{9}-\frac{4}{5} \times 1 \frac{1}{9} \div \frac{8}{15}-\frac{3}{4}+\frac{3}{4} \div \frac{1}{2}$ is:

In a class, 20% of the students are under 10 years of age. The number of students who are more than 10 years old is one third of the number of students who are 10 years old. If there are 24 students who are 10 years old, then how many students are there in the class?

The average weight of a certain number of persons in a group is 78 kg. If 4 persons having average weight 80.75 kg leave the group, the average weight of the remaining persons becomes 77.725 kg. The number of persons, initially, is:

The compound interest on a certain sum for 2 years at $15 \%$ p.a. is ₹ 7,282 , interest being compounded 8 -monthly. What will be the amount of the same sum at the same rate for the same duration, when the interest is compounded yearly?

A dealer sells an article by allowing a $20 \%$ discount on its marked price and gains $25 \%$. If the cost price of the article is increased by $10 \%$, how much discount percentage should he allow now on the same marked price so as to earn the same percentage of profit as before?

What is the least number which should be added to 3432 so that the sum is exactly divisible by 10, 5, 4 and 2?

A and B together can finish a work in 10 days, B and C together can finish the same work in 15 days, and A and C together can finish the same work in 20 days. In how many days can c alone finish the same work?

A solid piece of iron in the form of a cuboid of dimensions 24.5 cm × 16.5 cm × 12 cm, is melted to form a solid sphere.

What is the radius (in cm) of the sphere? (Use π = $\frac{22}{7}$)