Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd letters from the given alternatives.

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 a-1a=1, then a2 + 1a2 ?

Find the value of 491321973

What number should be added to each of 4, 16, 18 and 58 so that the resulting numbers will be in proportion in the given order?

If the difference between the measures of the two smaller angles of a right angled triangle is 8°, then the smallest angle is

A right circular cylinder is partially filled with water. Two iron spherical balls are completely immersed in the water so that the height of the water in the cylinder rises by 4 cm. If the radius of one ball is half of the other and the diameter of the cylinder is 18 cm, then the radii of the spherical balls are

Alipta got some amount of money from her father. In how many years will the ratio of the money and the interest obtained from it be 10:3 at 6% simple interest per annum?