Quantitative Aptitude - Arithmetic Ability Questions

What is the value of (32 cos6x – 48 cos4x + 18 cos2x – 1)/[4 sin x cos x sin (60 – x) cos (60 – x) sin (60 + x) cos (60 + x)]?

Select the related number from the given alternatives.
0.02 : 0.002 :: 1/3 : ?

The difference between simple interest on a certain sum at the rate of 6% per annum for 5 years and 6 years is 25.8. What is the sum (in Rs)?

(251+252+253+254+255) is divided by

Of the 5 numbers whose average is 72, the first is 1/8 times the sum of other 4. The first number is _____.

Both S.I. and C.I. is calculated with a similar rate of 10% per annum on a sum of rupees. If C.I. is calculated yearly for two years, then for what period must S.I. be evaluated such that S.I. = C.I.?

The sum of a fraction and 3 times its reciprocal is 19/4. What is the fraction?

Makarand works 2 times as fast as Samarjit. If Samarjit can complete a job alone in 27 days, then in how many days can they together finish the job?