Answer:
Total weight of the wheat placed on 45th square will be = 
Step-by-step explanation:
King rewarded the inventor of chess by giving grain of wheat on every square of the chess board. He places one grain of wheat on first square, 2 on second, 4 on 3rd, 8 on 4th and so on.
In fact he places grains of wheat in a progression S = 1, 2, 4, 8, 16.........n terms where value of n is 64.
We can rewrite the progression as S = 2°, 2, 2², 2³,.........n terms (n = 64)
In a geometric progression we know the nth term = 
where a = first term of the series, r = common ratio, n = number of terms
Now we have to calculate the weight of all wheat placed on 45th square.
So we will put the values in the given formula 45th term =
=
=
Then the weight of wheat will be =
=