Question

A blueprint for a picnic table has a scale of 1:20. The table in the blueprint is 3 in. long. What is the length of the actual picnic table?

A.) 5 feet

B.) 720 feet

C.) 5 inches

D.) 60 feet

Answer 1

The blue print has a scale of 1:20. So every 1 inch represents 20 inches of the actual size. so 3 inches represents 20*3 of the actual table = 60 inches
12 inches is 1 feet
so 60 inches =60/12 = 5 feet
The correct answer is 5 feet.

Answer 2

Option A is correct

5 feet is the length of the actual picnic table

Explanation:

Proportion states that two ratios or fractions are equal.

As per the statement:

A blueprint for a picnic table has a scale of 1 : 20.

The table in the blueprint is 3 in. long.

Let x be the length of the actual picnic table.

By definition of proportion;

`(1)/(20) = (3)/(x)`

By cross multiply we have;

`x = 20 \cdot 3 = 60`

⇒x = 60 inches

Use conversion:

1 inches =
`(1)/(12)` feet

then;

60 inches =
`(60)/(12) = 5` feet

Therefore, the length of the actual picnic table is, 5 feet