Quantitative Aptitude - Arithmetic Ability Questions

Working together, pipes A and B can fill an empty tank in 10 hours. They worked together for 4 hours and then B stopped and A continued filling the tank till it was full. It took a total of 13 hours to fill the tank. How long would it take A to fill the empty tank alone?

A person lent certain sum of money at 5% per annum simple interest and in 15 years the interest amounted to Rs 250 less than the sum lent. What was thesum lent (in Rs)?

The mean of a distribution is 20 and the standard deviation is 4. What is the value of the coefficient variation?

If (-1/2) * ( x - 5) + 3 = -5/2, then what is the value of x?

Find equation of the perpendicular bisector of segment joining the points (2,­6) and (4,0)?

The mean of a distribution is 21 and the standard deviation is 7. What is the value of the coefficient variation?

Select the odd number from the given alternatives.

select the odd word/letters/number/number pair from the given alternatives.