Quantitative Aptitude - Arithmetic Ability Questions

The arithmetic mean of the marks scored by students of a class is 58. 20% of them secured a mean score of 60. The mean score of another 30% of the students was 40. The mean score of the remaining students is

What is the slope of the line perpendicular to the line passing through the points (8,­2) and (3,­1)?

The area of a rhombus is 24 m2 and the length of one of its diagonals is 8 m. The length of each side of the rhombus will be:

Coefficient of x2 in (x + 7)(5 - 3x)(3x - 6) is

If a4 + 1 = [a2 /b2 ] (4b2 – b4 – 1), then what is the value of a4 + b4?

Triangle DEF is right angled at E. If cot D = 5/12, then what is the value of sin F?

What is the value of √[(1 + sinA)/(1 -­ sinA)]?

A work can be completed by 18 boys in 24 days. If 6 boys leave after working for 12 days, then how many days will be needed to complete the remaining work?