Question

question: 15
the ap exam does not use for loops and while loops, but rather repeat or repeat until commands as shown below.
repeat n times
{
<block of statements>
}
repeat until(condition)
{
<block of statements>
}
consider the following program, which is intended to print the sum of all the positive integers up to number.
sum ← 0
repeat number times
{
sum ← sum + number
}
display sum
which of the following best describes the behavior of this program?
the program correctly displays the sum of all positive integers from 1 to number
the program does not work as intended but rather it displays the number squared.
the program does not work as intended but rather it displays the number factorial.
the program does not work as intended because sum should be initialized to 1.

Explanation:

Step1: Analyze the loop

The loop REPEAT number TIMES adds number to sum each iteration. So after the loop, sum = 0 + number+number+\cdots+number (with number terms).

Step2: Calculate the sum

Using the formula for repeated addition, \(sum = number\times number=number^{2}\).

Answer:

The program does not work as intended but rather it displays the number squared.