Math Word Problem Average

Question

The average annual number of cigarettes smoked by an adult in some country continues to decline. For the years 1997-2006, the equation y=-49.2x+1756.7 approximates this data. Here x is the number of years after 1997 and y is the average annual number of cigarettes somked. If this trend continues, find the year in which the average annual number of cigarettes smoked is zero. To do this let y=0 and solve for x. (Round down to the nearest year)

Answer 1

y= -49.2x + 1756.7

0= -49.2x + 1756.7

-1756.7 = -49.2x

-1756.7 /  -49.2 = -49.2x / -49.2

x = 35.705 We will round down the result so x = 35

 

 

When x=35 that is 35 years after 1997. The year in which the average annual number of cigarettes smoked is zero is 1997 + 35 = 2032

 

The answer is 2032