Quantitative Aptitude - Arithmetic Ability Questions

When [x + (1/x)] = 5, then what is the value of [x – (1/x)]?

Find the curved surface area (in cm2) of a right circular cone of diameter 28 cm and slant height 12 cm.

The percentage change of a number when it is first decreased by 10% and then increased by 10% is

If cos4θ-sin4θ=13 then the value of tan2θ is

50 litre mixture of water and alcohol contains 10% alcohol. How much more alcohol must be added to make the strength of alcohol 40% in the new mixture?

Two cyclists P and Q cycle at 20 km/hr and 16 km/hr towards each other respectively. What was the distance (in kms) between them when they started if they met after 40 minutes?

X does 25% of a work in 20 days. Y joins X and they together finish the remaining work in 15 days. Y alone can do the whole work in ___ days.

The reciprocal of the sum of the reciprocals of 3/8 and 8/11 is: