How do I solve this challenge?

Hey Alex... You are on the right path, but as your isNotDivisible function is implemented now, it will not compile, since you are only returning a value (false) when it is NOT divisible... Now to fix it so it will compile, you should return a value in all circumstances - you have to do this every time you implement a function with a return value. Do you understand?

Now for the task itself, it seems the concept confuses you a bit. When running the function isNotDivisible you would expect to get a value of true if the numbers are in fact NOT divisible - but you return false. But try to always think about reusing your code. In this case you already have a function that returns a boolean value of whether or not the numbers are divisible, so your new isNotDivisible should always return the exact opposite. When working with booleans this is quite simple, and you can do the following:

func isNotDivisible(#dividend: Int, #divisor: Int) -> Bool {
    return !isDivisible(dividend: dividend, divisor: divisor)
}

Nb. Note the "!" in front of the function call, which is what inverts the boolean that we get back from isDivisible :)

Hello Alex:

You were on your way there, all you were missing was the right returns. Remember that when using conditional statements the IF statement in its simplest form has a single if condition, and it will execute a set of statements only if the condition is true.

// These two examples are IF statements it it’s simplest form

if 2 > 1 {
// It will execute because is true that 2 is higher than 1
}

if 1 > 2 {
// This will not execute because is NOT true that 1 is higher than 2
}

“The if statement can provide an alternative set of statements, known as an else clause, for when the if condition is false. These statements are indicated by the else keyword:”

I recommend reading. “The Swift Programming Language (Swift 2 Prerelease).” iBooks. https://itun.es/us/k5SW7.l

if 1 > 2 {
// It  will skip this since its not true
} else {
// it will execute because it is false
}

Here is the answer to your challenge.

func isNotDivisible(#dividend: Int, #divisor: Int) -> Bool {
    if dividend % divisor != 0 {
        return true
    } else {
        return false
    }
}

From what I saw on your code, it seems as if you didn’t understand the conditional statement part, that’s why I gave you this answer, if your confusion was the return concept, then please let me know and I can try to explain that better.

Hope this answer helps you.