Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd letter/letters from the given alternatives.

If a + b = 8 and ab = 15, then what is the value of a3 + b3?

A boat covers 143 km upstream in 13 hours and the same distance downstream in 11 hours. What is the speed (in km/hr) of the boat in still water?

If cost price of 5 cars is equal to selling price of 4 cars. Find the percentage of profit or loss?

The sum of two fractions is 5/6. One of them is 3/4, what is the other fraction?

Rizvan walks at 15 km/hr and Ruchitha cycles at 20 km/hr towards each other. What was the distance between them when they started if they meet after 42 minutes?

The total surface area of a hemisphere is 166.32 sq cm, find its radius?

The radius of base of a solid cylinder is 7 cm and its height is 21 cm. It is melted and converted into small bullets. Each bullet is of same size. Each bullet consisted of two parts viz. a cylinder and a hemisphere on one of its base. The total height of bullet is 3.5 cm and radius of base is 2.1 cm. Approximately how many complete bullets can be obtained?