Question

On a blueprint, the scale says that 2 cm represents 3 m. What is the actual length of a wall if its measurement on the blueprint is 7 cm?

Answer 1

10.5 metres

Explanation:

2 cm is equal to 3m

1 cm is equal to 1.5 m

7 cm is equal to 1.5 x 7 m which is 10.5 metres.

Answer 2

The actual length of the wall is 10.5 m

Explanation:

Write and solve an equation of ratios to answer this question:

2 cm 3 m

--------- = ---------

7 cm L

Solve this for L by inverting both sides:

7cm L

---------- = --------

2 cm 3 m

and then multiplying both sides by 3m:

21

----- = L

2

The actual length of the wall is 10.5 m