Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd letter/letters from the given alternatives.

If three successive discounts of 20%, 30% and 40% are given, then what will be the net discount (in percentage)?

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

If 1+121+141+161+181-131-151-17 = 1+ 1x, then what is the value of x?

If cosec 45° - sin 30° = x, then x is

If (1 + sinA)/cosA + cosA/(1 + sinA) = x, then the value of x is

A box contain equal number of 1 rupee, 2 rupee and 5 rupee coins. If the total amount is Rs 184, then how many coins of each type are there?

What is the value of (tan60 + 1/3) ?