Quantitative Aptitude - Arithmetic Ability Questions

The mean height of 25 boys in a class is 150 cm, and the mean height of 35 girls in the same class is 145 cm. The combined mean height of 60 students in the class is ___ (app)

5 years ago the average age of a family which includes father, mother and a son was 35 years. 3 years ago the average age of father and mother was
46 years. What is the present age (in years) of the son?

A, B and C can together do a job in 9 days. C alone can do the job in 36 days. In how many days can A and B do 50% of the job working together?

If cot2A -­ cos2A = x, then value of x is

A is thrice as productive as C. Together they can complete a job in 22.5 days. If B joins them after they have worked for 15 days then in how many days can they finish the rest of the job if B alone can do the job in 15 days?

A shopkeeper purchased 10 boxes of pencils containing 10 pencils each at Rs. 100 per box and sold each pencil at a profit 12%. What is the total sale price?

On selling rice for Rs. 45 per kg, a shopkeeper bears loss of 20%. To earn a profit of 20%, the selling price should be

Profit obtained on selling an article for Rs 540 is equal to the loss incurred on selling the article for Rs 370. If selling price is Rs. 910, then what is the profit percentage?