Quantitative Aptitude - Arithmetic Ability Questions

Select the related word/letters/number from the given alternatives.
1 : 8 :: ? :64

If the value of √42 is approximately 6.480, then what is the approximate value of √(6/7)?

If a+b=5 then the value of a-37+b-27 is

In what time(in years) will Rs. 8000 amount to Rs. 9261 at 5% per annum, compounded annually?

If cos 27° = x, the value of tan 63° is

7 litres mixture of milk and water contains 30% water. 3.5 litres of milk is added to this mixture. What is the percentage of water in the new mixture?

The mean of the 5 smallest numbers from a group is 15 while the mean of all the 13 members of the group taken together is 17. What is the mean of the 8 largest numbers?

The diameters of two cylinders are in the ratio 3:2 and their volumes are equal. The ratio of their heights is