Question

A chessboard has 64 squares. George places 1 grain of rice on the first square, 2 grains on the second square, 4 grains on the third square, 8 grains on the fourth square, and so on, until he has placed grains of rice on 10 squares

Answer 1

Total grains =1023 grains

Explanation:

Number of grains on 1st square = 1

Number of grains on 2nd square = 2

Number of grains on 3rd square = 4

Number of grains on 4th square = 8

Number of grains on 10th square = 512 grains

Total number of grains =?

Total number of grains in the 10 squares = S10= a(r^n-1)/r-1

=1(2^10-1)/2-1

=1(1024-1)/1

=1024-1 = 1023

Total number of grains in 10 squares = 1023 ....