18

18

1)
n = 30;
A = randi([-10 10], 1, 30)
zeros = 0;
pos = 0;
neg = 0;

for a=1:n
    if A(a) > 0
        pos = pos + 1;
    elseif A(a) < 0
        neg = neg + 1;
    else
        zeros = zeros + 1;
    end
end

disp('Number of positive numbers:'); disp(pos);
disp('Number of negative numbers:');disp(neg);
disp('Number of zeros:');disp(zeros);


3)
syms n
f = 7^(log(n)) ;
y = symsum(f, n, 2, Inf);
b = eval(y);
disp(b)

4)
m=10;
A = randi([0,100], 1 ,m)
n = input('Enter number: ');
dist = 100;
index = 0;
for a = 1 : m
    if abs(n - A(a)) < dist
        dist = abs(n - A(a));
        index = a;
    end
end

disp(A(index))

5)
m=30;
A = randi([0,20], m)
zeros = 0;

for a = 1 : m
    for b = 1 : m
        if A(b,a) == 0
            zeros = zeros + 1;
        end
    end
    if zeros >=3
        for d = 1 : m
            A(d,a) = 1;
        end
    end
    zeros = 0;
end

disp(A)