Quantitative Aptitude - Arithmetic Ability Questions

A tetrahedron has 4 vertices. How many edges does it have?

If x2+1x2-6, then find the value of 2x(x-1)x3-x2-x+1

The salary of a person is reduced by 20% . To restore the previous salary, his present salary is to be increased by

The vertical angle A of an isosceles triangle ΔABC is three times the angle B of it. The measure of the angle A is

A circle and a square have same area. The ratio of the side of the square to the radius of the circle will be:

Simple interest on a certain sum of money for 3 years at 18% per annum is half the compound interest on Rs. 9000 for 2 years at 10% per annum. The sum placed on simple interest is:

What is the largest 4 digit number which is exactly divisible by 81?

Shivam is 10% less efficient than Vivek. If Vivek can make a helmet in 9 days, then in how many days Shivam can complete the same work?