Quantitative Aptitude - Arithmetic Ability Questions

What is the average of all numbers between 100 and 200 which are divisible by 13?

X can complete a task in 8 days, whereas Y can complete the same task in 10 days. If they work together, in how many days will the task be completed?

The ratio of two numbers is 3 : 7. If their product is 1344, then what is the sum of both the numbers?

A can do a piece of work in 20 days and B in 15 days. With help of C, they finish the work in 5 days. C can alone do the work in

If a - b = -1 and ab = 6, then what is the value of a3- b3?

In a triangle PQR, PX, QY and RZ be altitudes intersecting at O. If PO = 6 cm, PX = 8 cm and QO = 4 cm, then what is the value (in cm) of QY?

In how many months will Rs 8,000 yield Rs 2,648 as compound interest at 20% per annum compounded semi-annually?

The weights of two iron balls are 3.5 kg and 7.5 kg. What is the percentage weight of the 1st ball with respect to 2nd ball.