Question

The following code is intended to calculate the sum of the first five positive odd integers. int sum = 0, k; for (k = 1; k <= 10; k += 2) { sum += k; } What is wrong with this code segment? a. The segment calculates the sum of the first four positive odd integers. b. The segment calculates the sum of the first six positive odd integers. c.The segment calculates the sum of the first seven positive odd integers. d. The variable sum is incorrectly initialized. The segment would work correctly if sum
was initialized to 1. e.The segment works as intended.

Answer 1

Calculate the sum of the first 5 positive odd integers: Let's do this in our head first, so we can check if our code is right or not!

The first positive 5 odd integers are: 1, 3, 5, 7, 9
Sum these to: 25

int sum = 0, k; <------These just declare our variables, telling the program 'Hey, I'm going to use 'sum' and 'k' to store data.

for (k = 1; <---We're going to repeat the following code, and we're starting at 1
k <= 10; <---- We're going to continue to repeat until we greater than 10.
k += 2) <------ Every time we do a loop, we're going to add 2.

{ sum += k; } <---- We're going to increase the number inside "sum" by the number inside "k"

Let's run this and see what happens. Remember, we keep going until we hit more than 10.

Round 0: k = nothing, sum = 0 (before we start the loop)
Round 1: k = 1, sum = 1
Round 2: k = 3, sum = 1+3 or 4
Round 3: k = 5, sum = 4 + 5 or 9
Round 4: k = 7, sum = 9 + 7 = 16
Round 5: k = 9, sum = 16 + 9 = 25
Round 6: k = 11, sum = 25 + 11 = 36

Well, we can tell here that round 5 was correct, but round 6 is not correct. And our loop condition says <=10, which means we have to do Round 6.

This means we did it one too many times. Our ending condition should be <10, instead of <=10. 

Option B