Why does two nearly identical statements show two different outcomes?

Question

I am doing a course with while, and there is a question:
You are making a ticketing system.
The price of a single ticket is $100.
For children under 3 years old, the ticket is free.

Your program needs to take the ages of 5 passengers as input and output the total price for their tickets.
and firstly i wrote:

passenger = 0
total = 0
while passenger <= 5:
age = int(input())
if age >= 3:
total += 100
passenger += 1
print(total)

and this gave me an EOF error while

passenger = 0
total = 0
while passenger != 5:
age = int(input())
if age >= 3:
total += 100
passenger += 1
print(total)

Was working. What is the problem with the first?

Answer 1

for first one, the loop will run 6 times, but you actually need 5 inputs for 5passenger

1st: passenger = 0, condition satisfies
2nd: passenger = 1, condition satisfies
3rd: passenger = 2, condition satisfies
4th: passenger = 3, condition satisfies
5tht: passenger = 4, condition satisfies
6th: passenger = 5, condition satisfies
7th: passenger = 6, condition doesn't satisfy, loop breaks

for 2nd one, works good,

1st: passenger = 0, condition satisfies
2nd: passenger = 1, condition satisfies
3rd: passenger = 2, condition satisfies
4th: passenger = 3, condition satisfies
5tht: passenger = 4, condition satisfies
6th: passenger = 6, condition doesn't satisfy, loop breaks....

so, if you had used "<5" in first code instead of "<=5" , it would have worked. Or else you could initialize passenger with "1" (passenger = 1), then it will work for first one

Answer 2

In your second code, you say while passengers !=5, which means while passengers <5.

Your first code includes 5 as a parameter.

To a computer, nearly the same is not good enough.
It must be exactly as stated.

I wish people were like that. 😔

Answer 3

In the first code, the while statement works 6 times. Cause passenger is 0 at initial and in the while, it says <= 5, so 0,1,2,3,4,5 you look it works 6 times. Also a solution, if you change passenger 0 to 1 at initially.

I hope, it's clear. Happy coding!