Quantitative Aptitude - Arithmetic Ability Questions

Choose the one which is different or odd from the following options?

Triangle PQR is such that PQ = 9 cm, QR = 6 cm, PR = 7.5 cm and triangle PQR is similar to triangle XYZ. If XY = 18 cm, find the value of YZ.

If x = (a/b) + (b/a), y = (b/c) + (c/b) and z = (c/a) + (a/c), then what is the value of xyz – x2 – y2 – z2?

Monika's father was 38 years of age when she was born while her mother was 36 years old when her brother four years younger to her was born. What is the difference between the ages of her parents?

What is the reflection of the point (-3, 1) in the line x = -2?

Two circles touch each other internally. The radius of the smaller circle is 6 cm and the distance between the centre of two circles is 3 cm. The radius of the larger circle is

The volume of a right circular cone, whose radius of the base is same as its altitude, and the volume of a sphere are equal. The ratio of the radius of the cone to the radius of the sphere is

10 people could complete a task in 8 days. After 4 days, 2 of the workers left. How many days from then did it take to complete the task?