Quantitative Aptitude - Arithmetic Ability Questions

A can do a piece of work in 8 days and B can do it in 10 days seperately. How many days would it take for both A and B to finish the same work together?

X and Y are two alloys which are prepared by mixing zinc and aluminium in the ratio of 1 : 4 and 11 : 8 respectively. If equal quantities of alloys are melted to form a third alloy Z then what is the ratio of zinc and aluminium in alloy Z?

What is the ratio of simple interest earned on certain amount at the rate of 12% for 6 years and that for 12 years?

The ratio of salary of X, Y and Z is 15 : 3 : 8. If Z gets Rs. 3960 more than Y, then what is the salary (in Rs.) of X?

Select the odd word/letters/number/number pair from the given alternatives.

If a + b = 1 and ab = -6, then what is the value of a3+ b3?

sinA/(1 + cos A) is equal to

If Sin θ = 12/13, then what is the value of Cot θ?