Quantitative Aptitude - Arithmetic Ability Questions

The average marks of 18 students in an examination was 60. It was later found that the marks of one student had been wrongly entered as 63 instead of 36. The correct average is:

A and B started a partnership business investing some amount in the ratio of 5 : 6. C joined then after 6 months with an amount equal to 2/3rd of B. What was their profit (in Rs) at the end of the year if C got Rs 21,600 as his share?

If each median of an equilateral triangle has a length of 12cm. Then what will be the value of in-radius (in cm) of the equilateral triangle?

56/32 simplified value?

∆PQR is right angled at Q. If sinP = 12/13, then what is the value of tanR?

A batsman scores 87 runs in the 21st match of his career. His average runs per match increases by 2. What was his average before the 21st match.

A cistern has one inlet, L and one inlet, M. L takes 5 hours to fill the empty tank, when M is not open and M takes 8 hours to empty the full tank, if the tank is two fifth full, how much time will it take to fill the tank completely when both L and M are opened simultaneously? (in hours)

The sum of twice a number and thrice its reciprocal is 25/2. What is the number?