Quantitative Aptitude - Arithmetic Ability Questions

One tap can fill a water tank in 50 mins and another tap can make the filled tank empty in 75 mins. If both the taps are open together, already half filled tank would be full in

The length of the radius of the circumference of a triangle having sides 9 cm, 12 cm and 15 cm is

In the following question, select the odd number from the given alternatives.

Oil equal to 20% of the weight of ground nut is extracted in a mill. The matter left after extraction is sold as cattle feed at the rate of Rs 12.5/kg. The groundnuts are bought at Rs 20/kg. The processing cost is Rs 5/kg. At what price (Rs per kg) should the oil be sold to earn 20% profit on total costs (Total cost = Cost of groundnuts and Processing costs)?

What is the difference (in Rs) in Compound interest earned in 1 year on a sum of Rs 10,000 at 40% per annum compounded quarterly and annually?

A race has three parts. The speed and time required to complete the individual parts for a runner is displayed on the following chart:
                       

                         Part I     Part II       Part III

Speed (kmph)       9            8              7.5

Time (minutes)     50          80             100

If  x = a + 1/a, y = a - 1/a, then the value of x4+y4-2x2y2

A, B and C start a business and the ratio of their investment is 8 : 5 : 3. If at the end the ratio of their profits is 4 : 15 : 6, then what is the ratio of time period of their investment?