Mathematical Science: Numbers and its type, Methods of Unit Measurement, Equations and Factors, Profit loss, Percentage, Simple and Compound Interest, Ratio-Proportion

By selling a chair for ₹ 1564, a shopkeeper suffers a loss of 15%. Find the cost price of the chair.

If the numbers 2, x, x, 8 are in proportion, then find x.

Find the largest three digit number, which will be completely divisible by number 8, 10 and 12.

The population of a city increases by 10% annually. If its present population is 20000, find the population of the city after 2 (two) years.

Aman's age is 15 years more than three times of Ravi's age. If Aman's age is 60 years, find Ravi's age.

How many prime numbers are there between zero and twenty?

Find the compound ratio of 3 : 5, 5 : 7 and 7 : 9.

The digits of a two digit number differ by 3, if the digits are interchanged and the resulting number is added to the original number, we get 143. What can be the original number ?

Multiply 7√5 by 3√5.

Shyam's father's age is 5 years more than three times Shyam's age. Shyam's father is 47 years old. Find Shyam's age.

Write the equation x = 2y in the form ax + by + c = 0, and find out the values of a, b and c.

Write a short note on Multiply 7√5 by 3√5 in 10 words.

A bag contains 50 p, 25 p and 10 p coins in the ratio 5 : 9 : 4, amounting to Rs. 206. Find the number of coins of each type.

A book was sold for Rs. 27.50 with a profit of 10%. If it were sold for Rs. 25.75, then what would have been the percentage of profit or loss ?

If the cost price is 96% of the selling price, then what is the profit percentage ?