John bought 24 pens and pencils. there were 6 more pens than pencils. how many pens were bought by john?

Let x represent the number of pens, and y represent the number of pencils.

We know that x + y = 24 (as it states in the question that altogether, there's 24 pens and pencils). We also know that x = y + 6 (as it also states that there were 6 more pens than pencils, which is number of pencils + 6).

So, given this information, we can rewrite our original expression of x + y = 24 by replacing the x with our second expression of x = y + 6:

x + y = 24

(y + 6) + y = 24

Now you just need to combine all the like terms and rearrange the expression to isolate the y value and find out the number of pencils:

(y + 6) + y = 24

2y + 6 = 24

2y = 18

y = 9

Now that you know that y (the number of pencils) = 9, you know that the number of pens will be 6 more than that, which is 9 + 6 = 15 (because the question says that there are 6 more pens than pencils).

Therefore, you have 15 pens and 9 pencils.