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 x = a cosθ+ b sinθ and y = b cosθ- a sinθ, then x2 + y2 is equal to

In ΔPQR, S and T are points on side PQ and PR respectively. ST is parallel to QR. If S divides PQ in the ratio 4:1 and length of QR is 15 cm,what is the length of ST?

ΔABC is right angled at B. If m ∠A = 60°, then what is the value of 1/√3 Cosec C?

Tanya got an increment of 15% in her salary. If her enhanced salary is Rs.14,030. What was her original salary?

The lengths of diagonals of a rhombus are 24cm and 10cm the perimeter of the rhombus (in cm ) is :

If a + b = 1, then a4 + b4 - a3 - b3 - 2a2b2 + ab is equal to

The mean of 10 observations is 17. One more observation is included and the new mean becomes 16. The 11th observation is