Question 18 What line (if any) of the following code has an error? n-10; m = 10; x = zeros(10,10); WN 1 for i = 1:m for j = 1:n if x(i,j) -- 255 x(i, j)= 0; end end 7 end No error Question 19 How many times will the following while loop run? fib - ones (1, 10); while i 10 fib (i) = fib (i-1) + fib (1-2); e 11 07 1 Question 24 What command is used to retain a plot so that you can print another plot in the same window O retain do again reprint hold on