data structures & algorithm

Question 7: (a) A man places one grain of rice on the first square of a chess board, then two grains on the second square, four on the third square, etc. - every time twice as many as before. Give the exact number of grains on square n as well as on the last square. Indicate accordingly what the growth rate is. (2 marks) (b) How many squares does one need to fill to get a billion grains of rice? How many, in general, to get M grains of rice? Justify your answers. (2 marks)