Quantitative Aptitude - Arithmetic Ability Questions

The value of(1(p-n)(n-q)+1(n-q)(q-p)+1(q-p)(p-n)) is

If p and q are the roots of the equation x2 –15x + r = 0 and p –q = 1, then what is the value of r ?

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

A profit of Rs. 960 is divided between A and B in the ratio 1/3:1/2. The difference of their profit is :

A does 80% of a work in 20 days. He then calls in B and they together finish the remaining work in 3 days. How long B alone would take to do the whole work?

A starts a taxi service by investing Rs 25 lakhs. After 3 months, B joins the business by investing Rs 40 lakhs then 4 months after B joined, C too joins them by investing Rs 50 lakhs. One year after A started the business they make Rs 2,73,000 in profit. What is C's share of the profit (in Rs)?

The average marks of 18 students in an examination was 60. It was later found that the marks of one student had been wrongly entered as 63 instead of 36. The correct average is:

If each median of an equilateral triangle has a length of 12cm. Then what will be the value of in-radius (in cm) of the equilateral triangle?