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)]?

Two numbers are 50% and 80% lesser than a third number. By how much percent is the second number to be enhanced to make it equal to the first number?

The average weight of 25 candles is 40 grams. If some candles of weight 50 grams each were removed, then average weight becomes 37.5 grams. How many candles of weight 50 grams each were removed? 

Two cyclists P and Q cycle at 20 km/hr and 25 km/hr towards each other. What was the distance (in kms) between them when they started if they met after 56 minutes?

In each of the following questions two equations I and II are given. Solve both the equations and give answer:
$$\begin{gathered} I. x2+2x-195=0 \\ II. y2+30y+225=0 \end{gathered}$$

The ratio of the sides of a triangular shaped park is 3 : 4 : 5 and the perimeter of the park is 170 m. What is the perpendicular distance in meters from the vertex, opposite to the largest side of the park?

Find the odd one out.

If x + 1/x = √13, then 3x(x2-1) equal to