Question

How much must a carpenter cut off a 48-inch board if the length must
be 40 ± 0.25 inches?

Answer 1

Explanation:

let 'x' represent the amount removed, then we require:

40-0.25 <= 48-x <= 40+0.25

which solves to:

7.75 <= x <= 8.25

the carpenter must saw off between 7.75 and 8.25 inches