Formula for percentage?

[Prozeen]

Hi, this is a mathematical question, but I'm doing it in VB so I thought I'd post it here...

A person is shown a total of 10 numbers. When a number appears on the screen they have to type that number into a text box and if they get it correct another number appears. If they do not get it correct they get another chance at getting the original number correct.

I'm trying to work out the accuracy of the values they input (and then I display that accuracy as a percentage when the program has finished.) For example, if they input 11 values (i.e. 1 of them is not the correct number) then I'm guessing the accuracy is approximately 90%. But what is the formula to obtain this figure/percentage?

Thanks.

[plusplus]

Do you let them try a second time with the original number and when they get it right the second time you still take off for that? Before you have a formula you have to have the exact rules.
Anyway, let me try to answer your question even without knowing the exact rules, you can adapt it accordingly
let's say you give them 10 questions
you have a variable called mistake. Every time they got an answer wrong you add 1 to mistake.
10 = 100% so for each mistake you take off 10%. So your formula would be
100-(mistake*10)

[zmariow]

You need to have 2 numbers to compute the accuracy:

• Number of successful attempts (call it s)
• Number of total attempts (call it t)

And here's the formula: accuracy = (s / t) * 100
Cheers :)

[Prozeen]

Thanks for the help guys. Okay, I tried running the program, using both the formulas you supplied at the same time. When I use the program with no incorrect answers I get...

plusplus = 0
zmariow = 10

And when I have one incorrect answer (i.e. 11 attempts for 10 numbers)...

plusplus = -10
zmariow = 9.090909

From what I can work out plusplus is close to the mark (probably due to my ambiguity) but it's not as accurate as zmariow. So, because I want to show it as a percentage, here's what I came up with...

res2 =(success / attempt) * 100 * 10
lblresults.caption "Your accuracy is  " and res2 & "%"

Is this right?

[zmariow]

...When I use the program with no incorrect answers I get...
plusplus = 0
zmariow = 10

Since you're getting 10 using my formula I assume you're doing something wrong when counting the number of mistakes and the total number.

This is because you should have s and t both equal to 10 and the formula should give you: 100... that is 10/10 * 100 = 100...

Can you show us what are the values of s and t??? (or whatever names you're using for those variables)

[Prozeen]

Okay, to cut a long story short, I finally got it. For some reason I had to declare "success" in the general declarations section. I don't know how, but it fixed the problem and now I'm using the exact code you provided zmariow. Thanks for that!

[zmariow]

You're welcome :)

I also advice you to investigate this declarations issue in order to avoid more problems later on.

Cheers:)