Quantitative Aptitude - Arithmetic Ability Questions

If a - b = 3 and a2+b2=25, then the value of ab is

Dodecahedron has 20 vertices. How many edges does it have?

At 5% simple interest per annum a certain sum yields a total amount of Rs. 2,790 at the end of 3 1/4 years. The sum invested was

A man starts walking at 6.30 a.m. and wants to cover a distance of 30km. His initial speed is 6 kmph and after covering three-fifth distance, he reduces his speed by 2 kmph. At what time will he complete his walk?

A solid right circular cone of radius 4 cm and height 7 cm is put inside a cylindrical vessel of radius 5 cm and height 8 cm. How much water in cubic cm will be required to fill the cylindrical vessel completely?

Find the odd word/letters/number pair from the given alternatives.

Find out the odd word/letters/number/number pair from the given alternatives.

What is the value of sec -2π/3 ?