Quantitative Aptitude - Arithmetic Ability Questions

The number of trees in a town is 17640. If the numbers of trees increases annually at the rate of 5%, then how many trees were there 2 years ago?

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

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

What will come in the place of question mark (?) in the following question (You do not have to calculate the exact value)?

√(3099.985 ÷ 62.001 + 14.001) = ?

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)]?

An aeroplane flying horizontally at a height of 3 Km. above the ground is observed at a certain point on earth to subtend an angle of 60°. After 15 sec flight, its angle of elevation is changed to 30°. The speed of the aeroplane (taking √3 = 1.732) is

Coefficient of x2 in (x + 9)(6 -­ 4x) 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.?