The sum of two numbers is 84 and their HCF is 12. Total number of such pairs of number is 

If pq+qr+rp=0 then find the value of $$ {p^{2}\over {p^{2}-qr}}+{q^{2}\over {q^{2}-rp}}+{r^{2}\over {r^{2}-pq}}$$

Unit digit in (264)¹⁰²+(264)¹⁰³ is:

The monthly salaries of A, B and C are in the ratio 2 : 3 : 5. If C's monthly salary is ₹ 12,000 more than that of A, then B's annual salary is 

A trader bought 10 kg of apples for Rs. 405 out of which 1 kg of apples were found to be rotten. If he wishes to make a profit of 10 % at what rate should he sell the remaining apples per kg? 

At present, the sum of the ages of A, B and C is 150 years, whereas 10 years ago, the ratio of their age was 5:4:3. Find the ratio of their ages 10 years hence.

Some amount out of Rs.7000 was lent at 6% per annum and the remaining at 4% per annum. If the total simple interest from both the fractions in 5 year was Rs.1600, find the sum lent at 6% per annum.