Ravi purchases 90 pens and sells 40 pens at a gain of 10% and 50 pens at a gain of 20%. Had he sold all of them at a uniform profit of 15% he would have got Rs. 40 less. Find the cost price of each pen.

Sarita sells a Phone at a profit of 20%. If she had bought it at 20% less and sold it for Rs. 180 less, she would have gained 25%. Find the cost price of the Phone.

Who was the President over the Cabinet Mission ?

Who wrote the Hitopadesha? 

Which dynasty issued the largest number of gold coins?

Which of the following is not true about graphene?

Which of the following is hotter?

Which of the following is an example of diffusion of gases?