Dog Barks/Cars Passing

Question

The number of times a dog barks is dependent on the number of passing cars. How many cars have passed when a dog barks 34 times if 6 cars pass and there are 4 barks, 7 cars pass and there are 7 barks, 8 car pass and there are 10 barks, 9 cars pass and there are 13 barks, 10 cars pass and there are 16 barks. Using this information, if 20 cars pass, how many times will the dog bark

Answer 1

f(x) = ax + b

 

4 = 6a + b

7 = 7a + b

3 = a

 

f(x) = 3x + b

4 = 18 + b

-14 = b

 

f(x) = 3x - 14

 

f(20) = 3(20) - 14

f(20) = 60 - 14

f(20) = 46