Quantitative Aptitude - Arithmetic Ability Questions

Find out the odd word/letters/number/number pair from the given alternatives.

If 1 + secA = x, then the value of x is

If (x+1/x) = 5, then the value of 5xx2+5x+1?

The ratio of number of boys and girls in a school of 720 students is 7 : 5 . How many more girls should be admitted to make the ratio 1 : 1 ?

Two cars travel from city A to city B at a speed of 30 and 45 km/hr respectively. If one car takes 2.5 hours lesser time than the other car for the journey, then the distance between City A and City B is:

A piece of work was finished by A, B and C together. A and B together finished 60% of the work and B and C together finished 70% of the work. Who among the three is most efficient?

Find the odd one out among the following.

If P = 7 + 4√3 and PQ = 1, then what is the value of (1/P2) + (1/Q2)?