Quantitative Aptitude - Arithmetic Ability Questions

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 Sin4A - Cos4A = 1 then (A/2) in degrees is 0° < A ≤ 90°

ABCD is a trapezium in which AB is parallel to CD and AB = 4(CD). The diagonals of the trapezium intersects at O. What is the ratio of area of triangle DCO to the area of the triangle ABO?

Rashika can do a work in 5 days. Rashmi can do the same work in 7 days. Both of them finish the work together and they get Rs 240 for the work. What isthe share (in Rs) of Rashika?

The average revenues of 7 consecutive years of a company is Rs 71 lakhs. If the average of first 4 years is Rs 66 lakhs and that of last 4 years is Rs 78 lakhs. What is the revenue for the fourth year.

If the length of the shadow of a vertical pole be √3 times the height of the pole, the angle of elevation of the sun is:­

cos(A+B) + cos(A-B) is equal to

Mukesh got series of discount 30%, 25%, 15% on his shirt. Find out the single equivalent discount.