Quantitative Aptitude - Arithmetic Ability Questions

If 4x - 5y = -37 and 7x + y = -16, then x - y = ______

P and Q can do a project in 20 and 12 days respectively. In how many days can they complete 40% of the project if they work together?

The mean score in a test of the 12 boys in a class was 16 while the overall mean of the 30 students in the class was 18.1. What was the mean score of the girls?

A trader buys 500 kgs of cotton for Rs 9,000. 10% of this cotton is spoiled due to rain. At what rate (Rs/Kg) should he sell the rest to earn 10% profit?

The greatest perfect square number of 6 digits is

A mixture of 240 litres of juice and water contains 15% water. How much more water (in litres) should be added to this so that the strength of water will become 25% in the new mixture?

Expanded and simplification of (x + 3)(x - 1) will be equal to

The 3rd and 9th term of an arithmetic progression are -8 and 10 respectively. What is the 16th term?