The ratio between the length and breadth of a rectangular field is 3 : 2. If the length is increased by 5 m, the new area of the field will be 2600 sq m. What is the breadth of the rectangular field?

If a sum of money doubles itself in 8 yr at simple interest, then the rate of interest per annum (in %) is

Ten years ago A was half of B in age. If the ratio of their present ages is 3 : 4, what will be the total of their present ages?

A retailer buys 30 pens from a wholesaler and pays equal to marked price of 27 pens. If he sells the pens at the marked price, his profit per cent in the transaction is

If the diameter of a cylinder is 20 cm and its height is 20 cm, then the surface area (in cm²) is

45% of √225 + 21 = ?

40 ÷ 0.80 ÷ 0.25 = ?

6085 − 4017 + 1496 − 1124 = ?

A contractor agreeing to finish a work in 150 days employed 75 men, each working for 8 h daily. After 90 days only 2/7 of the work was completed. How many more men would be put on now, each working 10 h daily so as to finish the work in the stipulated time?