Question

A young mother is attempting to clean the house while her 2 children, ages 5 and 2, play in the living room. The older child begins feeding lego bricks to the younger at a constant rate. Below is a chart of how many bricks remain yet to be consumed after a given number of minutes.

Time (minutes): 4 6 11 17

Bricks remaining: 75 69 54 36

How many lego bricks were there before the un-attentive mother began cleaning?

Answer 1

87

Explanation:

f(x) = ax + b

f(4) = 75 => 4a+b = 75

f(6) =69 => 6a+b = 69

________-

-2a = 6

a = 6/-2 = -3

4a + b = 75

4(-3) +b=75

-12+b = 75

b = 75+12

b = 87

the number of lego bricks before the mother began cleaning = 87