Question

Jiah is building birdhouses. It takes her 51/2 hours to build 4 birdhouses. Which of the following is an equivalent rate?

a)14 hrs to build 18 houses
b)28 hrs to build 35 houses
c)11 hrs to build 8 houses
d)22 hrs to build 28 houses

Answer 1

Answer:  The correct option is

(c) 11 hrs to build 8 houses.

Step-by-step explanation:  Given that Jiah is building birdhouses. It takes her 5.5 hours to build 4 birdhouses.

We are to select the equivalent rate.

We will be using the UNITARY method to solve the problem.

According to the given information, we have

Time taken to build 4 birdhouses = 5.5 hours

So, time taken to build 1 birdhouse will be

$\dfrac{5.5}{4}=1.375~\textup{hours}.$

Option (a): 14 hrs to build 18 houses

Time taken to build 18 birdhouses is given by

$18\times1.375=24.75\neq14.$

So, this rate is not equivalent.

Option (b): 28 hrs to build 35 houses

Time taken to build 35 birdhouses is given by

$35\times1.375=48.125\neq28.$

So, this rate is not equivalent.

Option (c): 11 hrs to build 8 houses

Time taken to build 18 birdhouses is given by

$8\times1.375=11.$

So, this rate is equivalent.

Option (a): 22 hrs to build 28 houses

Time taken to build 18 birdhouses is given by

$28\times1.375=38.5\neq22.$

So, this rate is not equivalent.

Thus, the correct option is

(c) 11 hrs to build 8 houses.

Answer 2

C) 11 hrs to buil 8 birdhouses