Question

The left and right page numbers of an open book are two consecutive integers whose sum is 355. Find these page numbers.

Answer 1

177 and 178

Explanation:

If they are consecutive numbers and add to 355, it means that 2 times their average will also add the 355. So to find their average, we can divide 355 by 2 which gives us 177.5

If we know that this is the number exactly between them and they are consecutive, then we just find the nearest whole number either side: 177 and 178, which gives us our page numbers.

Answer 2

177 and 178

Explanation:

Let's let the first page number be n. Then the next page number must be (n+1).

And together, we know that they total 355. So:

`n+(n+1)=355`

Combine like terms:

`2n+1=355`

Subtract 1 from both sides:

`2n=354`

Divide both sides by 2:

`n=177`

So, the first page number n is 177. And the other is 178.

And we're done!