In a class of 60 students 55% are boys. The number of girls in the class is :

4, 9, 25, 49, 121, 169, ................

The three-fifth of a number is 40 more than the 40 percent of the same number. The number is :

103²-97²

An amount is divided among P,O,R in the ratio 2:5:7 if P’s share is Rs 3,000 then the diference between the shares of Q and R is :