Question

Which situation could be modeled using a DIRECT proportion? A) It takes 3 people 5 hours to dig a hole. Bill wants to know how many people it will take to dig the same hole in 3 hours. B) Sally uses 2 cups of sugar to make 4 dozen cookies. She needs to know how many cups to use if she wants to make 6 dozen cookies. C) In math class each group must complete 25 problems. Group A has 4 members and it takes them 45 minutes. Group B wants to know how long it will take them with 6 members. D) Amy drove to New Orleans from Birmingham at an average of 60 mph, and it took her 5 hours. Beth wants to know how long it will take her to make the same trip traveling 70 mph.

Answer 1

The Answer is A because it is proportion to the numbers

Answer 2

Answer: B) Sally uses 2 cups of sugar to make 4 dozen cookies. She needs to know how many cups to use if she wants to make 6 dozen cookies.

Explanation:

Direct proportion refers to two or more quantities either increase or decrease together.

Let's check all the given options.

A) When time to do a job decreases then the number of workers increases or vice-versa.

It means it represents inverse proportion.

So this situation could not be modeled using a DIRECT proportion .

B) The quantity of cookies is directly related to quantity of sugar.

So to make 6 dozen cookies rather than 4 dozen , the amount of sugar require would increase .

It means this situation could be modeled using a DIRECT proportion .

C) Time is inversely related to the number of persons require to do a job.

So this situation could not be modeled using a DIRECT proportion .

D) Speed is inversely related to time when distance remains constant.

So when average of 60 mph increases to an average of 70 mph , the time taken to drove to New Orleans from Birmingham decreases.

Hence, the situation could be modeled using a DIRECT proportion is :

B) Sally uses 2 cups of sugar to make 4 dozen cookies. She needs to know how many cups to use if she wants to make 6 dozen cookies.