Question

Dr. Irvine saw 130 patients in one week. The ratio of kids to adults that he saw is 3 to 7. If k represents the number of kids and d represents the number of adults, which system of equations should be set up to find out how many kids Dr. Irvine saw during the week?
A. k+d=130
3k = 7d

B. 3k+7d=130
3k = 7d

C. k+d=130
7k = 3d

D. 3k+7d+130
7k = 3d


Please help, will mark brainliest.

Answer 1

Answer:

The correct answer is

C. k+d=130

7k = 3d

Number of kids Dr. Irvine see in a week is 39.

Step-by-step explanation:

1. Let's review the information given to answer the question correctly:

Number of patients Dr. Irvine see in a week = 130

Radio of kids to adults = 3:7 or 3/7

Number of Kids = k

Number of adults = d

2. Let's find the equations system that should be set up to find out how many kids Dr. Irvine see

k + d = 130 (Number of patients Dr. Irvine see in a week)

Including the ratio:

7k = 3d

Replacing d:

d = 130 - k

Now substituting:

7k = 3 * (130 - k)

7k = 390 - 3k

10k = 390

k = 390/10

k = 39