Quantitative Aptitude - Arithmetic Ability Questions

The reciprocal of the sum of the reciprocals of 2/9 and 7/10 is

If the radius of a circle is increased by 16%, its area increases by

Ticket for an adult is Rs 2200 and a child is Rs 990. One child goes free with two adults. If a group has 23 adults and 11 children, what is the discount the group gets?

The area of the circle with radius Y is W. The difference between the areas of the bigger circle (with radius Y) and that of the smaller circle (with radius X) is W'. So x/y is equal to

When a number is increased by 18, it becomes 106% of itself. What is the number?

If x+1x ≠0 and x3+1x3 = 0, then the value of x+1x4 is :

If cot(A/2) = x, then x is equal to

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