Quantitative Aptitude - Arithmetic Ability Questions

For what value of k, the expression x6– 18x3 + k will be a perfect square?

The average age of a class of 39 students is 15 years. If the age of the teacher is included, then the average increases by 3 months. Find the age of the teacher.

The average of marks of 17 students in an examination was calculated as 71. But it was later found that the mark of one student had been wronglyentered as 65 instead of 56 and another as 24 instead of 50. The correct average is

The simple interest on Rs. 2000 for 2 years at Rs. 75 per thousand per annum will be

Robin can do a work alone in 9 days. Amit can do the same work alone in 6 days. Both of them finish the work together and they get a total Rs 2500. What isthe share (in Rs) of Robin?

A can do a work in 21 days and B in 42 days. If they work on it together for 7 days, then what fraction of work is left?

A and B together do a job in 6.75 days and A could do the job in 9 days if he worked alone. How many days would B take to do the job if he worked alone?

3/5 of my current age is the same as 5/6 of that of one of my cousin. My age ten ago will be his age four years hence. My current age is ___ years.