$x^2-y^2$=16 and xy = 15 so find out x + y

Census population of a district in 1981 was 4.54 Lakhs, while in year 2001 it was 7.44 Lakhs. What was the estimated mid-year population of that district in year 2009.

Find the maximum value of n such that 50! is perfectly divisible by $2520^n$ .

A girl leaves from her home. She first walks 30 metres in North-west direction and then 30 metres in South-west direction. Next, she walks 30 metres in South-east direction. Finally, she turns towards her house. In which direction is she moving?

There is well of depth 30 m and frog is at bottom of the well. He jumps 3 m in one day and falls back 2 m in the same day. How many days will it take for the frog to come out of the well?

Find the next term in the given series
47, 94, 71, 142, 119, 238, _ ?

A train leaves Meerut at 5 a.m. and reaches Delhi at 9 a.m. Another train leaves Delhi at 7 a.m. and reaches Meerut at 10.30 a.m. At what time do the two trains travel in order to cross each other ?

`A` and `B` started a business in partnership investing Rs 20000/- and Rs 15000/- respectively. After six months `C` jointed them with Rs 20000/-. What will be B`s share in the total profit of Rs 25000/- earned at the end of two years from the starting of the business?

What is the 8th term in the series 1, 4, 9, 18, 35, 68, . . .

In a cycle race there are 5 persons named as J, K, L, M, N participated for 5 positions so that in how many number of ways can M make always before N?