I am practicing questions in which I need to determine the big oh time complexity for a given piece of code. I have attempted the first 3 questions. Could anyone please confirm if the answers are  correct?Also, I am not sure how to calculat the big oh time complexity of the code in the 4th question. Could someone please explain how to calculate it?Thank you1:sum, i = 0, 0 while i**2 < n:    sum = sum + i     i += 2O(n^(1/2))2.i, j, sum =1,1,0 while i < n**3:    while j < n:         sum=sum+ i        j += 1     i=i+nO(n^3)3.i, sum = 0, 0 while i *2 < n:    sum = sum + i     i=i+1O(log(n))4.i, sum =0,0 while i < 3 * n:    if i %2 == 0:        j = 1        while j < n:            sum = sum + j            j=j*2     else :        j = 1        while j < n:            sum = sum * j            j += (n // 5)     i=i+5
Determining big oh time complexity
asymptotics