Quantitative Aptitude - Arithmetic Ability Questions

If 3cos2x - 2sin2x = -0.75 and 0°⩽ x ⩽ 90°, then x = ?

If x - √x = 20; Find the value of √x.

If 5x + 4(1 -­ x) > 3x - ­4 > 5x/3 -­ x/3; then x can take which of the following values?

Two trains are moving in the same direction at the speed of 42 km/hr and 84 km/hr, their lengths are 320 metres and 380 metres respectively. What is the time taken (in seconds) by faster train to cross the slower train?

Find the greatest number which on dividing 1580 and 3800 leaves remainders 8 and 1 respectively.

A shop keeper purchased 15 kg of sugar and 20 kg of wheat at Rs. 50 and Rs. 75 per kg respectively. On selling them, he gained 10% on sugar and 20% on wheat. What was the total sale vale?

The curved surface area and the slant height of a right circular cone are 858 cm² and 13 cm respectively. Find its diameter (in cm).

Pipe A can fill an empty cistern in 4 hours while along with Pipe B it can fill it up in 3 hours. Only Pipe A is turned on for an hour after which Pipe B is also turned on. How much total time will it take to fill up the cistern?