What is output? C = 1
sum 0
while (c < 10):
c = c + 3
sum
sum + C
print (sum)

The output of this question is 21. As show in the image

The explanation is given in below

Explanation:

Let first write the question

C=1

sum = 0

while(C<10):

C=C+3

sum=sum + C

print(sum)

Now Focus on

while(C<10):

C=C+3

sum=sum + C

The value of C is initially 1

C=1+3

Sum= 0+4

In second loop the value of C will become 4

c=4+3

sum=4+7

In third loop the value of C will be 7

c=7+3

sum=11+10

so the answer is 11+10=21