Quantitative Aptitude - Arithmetic Ability Questions

A boat goes 8 km upstream and 12 km downstream in 7hours. It goes 9 km upstream and 18 km downstream in 9 hours. What is the speed (in km/h) of the boat in still water?

In new government policy, the price of onion is raised by 35%. By what % should a person reduce onion consumption so that the expenditure on it does not increase?

If ab+ba = -1, then the value of a2b-b2a is

If the elevation of the Sun changes from 30° to 60° , then the difference between the lengths of shadows of a pole 15 m high, is

If 12x = 192- 112, what is the value of x?

Rahul’s salary is 40% of Mohit’s salary. If Rahul’s salary is increased by 60% and Mohit’s salary is decreased by 20%, then Rahul’s salary will be how much percentage of Mohit’s salary?

A contractor has got two orders A and B. On one (A) he spends Rs. 25,000 and makes a bill of Rs. 30,500. On the other (B) he makes a bill keeping a profit of 20%. Which of the two orders is more profitable to him?

The selling price of an item inclusive of a 10% profit was Rs.440. What would be the percentage loss if the item was sold for Rs. 370?