42

eh … OK then. 16.

Could also be written in a more classical way like:

8 8 ( 1 + 3 ) 8 + 24 32

--- (1 + 3) = -------------- = ---------- = ----- = 16

2 2 2 2

One could of course also take the simpler / more direct? approach with normal precedence and associativity, (here from K&R p. 53 (p. 66 in PDF))

* Parenthesis have highest precedence in the given exercise

* Division and multiplication have same, and are applied left to right

8 ∕ 2 × (1 + 3)

= 8 / 2 × 4

= 4 × 4

= 16

or, if you like:

8 ∕ 2 × (1 + 3)

= (8 / 2) × (1 + 3)

= 4 × 4

= 16

or:

8 ∕ 2 × (1 + 3)

= 4 × (1 + 3)

= 4 + 12

= 16

etc.