Quantitative Aptitude - Arithmetic Ability Questions

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

A, B and C can finish a job working alone in 72, 24 and 36 days respectively. In how many days they can finish the job if they worked together?

For triangle PQR, find equation of altitude PS if co-­ordinates of P, Q and R are (1,2), (2,­-1) and (0,5) respectively?

In the following question, four groups of three numbers are given. In each group the second and third number are related to the first number by a Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

If a + b = 10 and ab- 13 = -ba - 11, then what is the value of 3ab + 4a2 + 5b2 ?

What is the value of 13×7+17×11+111×15+...+1899×903 ?

In a rectangle _____.

Find the number of prime factor of 1024.