C and D started a business by investing Rs 4000 and Rs 5000 respectively. After 3 months, C withdraws Rs 1000 while D invest Rs 1000 more after 6 months of the starting of business. At the end of the year C’s share is Rs 3900. What will be the total profit (in Rs) at the end of year?

If a/b = c/d = e/f = 2/5, then what is (5a + 3c + 2e) : (5b + 3d + 2f)?

If A% of A is 196, then what is the value of A?

The line parallel to the BC of the triangle ABC divides the other two sides at the point D and E in such a way that AB=3AD. Calculate the ratio of DE and BC.

A triangle is circumscribed on the circle of centre O in such a way that sides AB = 12 cm, BQ = 7 cm and CQ = 5 cm. Calculate the lengtth (in cm) of side AC.

Find the value of  x3 - y3, if x - y = 4 and xy = 12.

Determine the value of a/b + b/a when a + b = 8 and ab = 4.

Find the unit place digit in the expression given below:

1! + 2! + 3! + 4! + ..... + 20!