Quantitative Aptitude - Arithmetic Ability Questions

In the following question, four number pairs are given. The number on left side of (–) is related to the number of the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

If sinθ x cosθ = 1⁄2 . The value of sinθ ­- cosθ is where 0°< θ< 90°

Which one of the following is true for 0°<θ<90°

If √(1 + cot2A) = x, then the value of x is

Product of digits of a 2-digit number is 72. If we add 9 to the number, the new number obtained is a number formed by interchange of the digits. Find the number.

Select the odd letters from the given alternatives.

If Sinx = 4/5, then Sec2x - 1 = ?

What is the x – intercept of the linear equation 18x + 25y – 900 = 0?