Find the area of the largest triangle made in a semicircle of r cm radius?

Pipes A and B can fill a tank in 12 minutes and 15 minutes, respectively. The tank when full can be emptied by pipe C in x minutes. When all the three pipes are opened simultaneously, the tank is full in 10 minutes. The value of x is:

Surekha borrowed a sum of money and returned it in two equal annual instalments of ₹5,547 each. If the rate of interest was $$7{1\over 2}\%$$ p.a. compounded yearly, then the total interest paid by her was:

A sum of Rs. 110 is in the form of Rs. 2, Rs. 1 and 50 paise coins in the ratio of 1 : 2 : 3, respectively. How many 50 paise coins are there?

The mean of 20 items is 55. If two items 45 and 30 are removed, what will be the new mean of the remaining items?

If one angle is half of its complementary angle, find that angle.

The area covered by a square is 308 square cm. The length of the diagonal of the square is.

Simplify : $$\sqrt{[(12.1)^2-(8.1)^2]÷[(0.25)^2+(0.25)(19.95)]} $$