Question

While building his deck Peter uses boards that are 14 cm wide. He leaves a gap of 2 cm between boards. If Peter makes a deck that is 20 boards wide, what is the total width of his deck?

Answer 1

20 × 14 =280
20 × 2 = 40
280 + 40 = 320

320 cm wide

Answer 2

318 cm . . . or 3.18 m

Step-by-step explanation:

2 boards have 1 gap. 3 boards have 2 gaps. 20 boards will have 19 gaps.

... total width = board width + gap width

... = 20×(14 cm) + 19×(2 cm)

... = 280 cm + 38 cm = 318 cm