If A and B are square matrices of the same order such that AB = A and
BA =B, then (A +B ) is equal to:

1. A - B
2. A + B
3. AB
4. None of these

If the amount is 2 ¼  times the sum after 2 years at compound interest, the rate of interest per annum is :

1) 25%

2) 30%

3) 40%

4) 50%

Mahesh bought 50 kg of wheat at Rs.8 per kg and 150 kg at the rate of Rs. 7 per kg. He sold the mixture to get 12% profit. At what price per kg did he sell the mixture?

1)  Rs. 7.37

2)  Rs  7.84

3)  Rs. 8.40

(4) None of these