The FAA tracks average flight delays. It found that, this year, a particular airline has an average flight delay of $37$ minutes. That is $85\%$ longer that the airline's average for the previous year. What was its average flight delay last year? $\newline$ ____ minutes

Full solution

Q. The FAA tracks average flight delays. It found that, this year, a particular airline has an average flight delay of

37

minutes. That is

85\%

longer that the airline's average for the previous year. What was its average flight delay last year?

\newline

____ minutes

Define Average Flight Delay: Let $x$ be the average flight delay last year. $\newline$ Calculate the expression for $85\%$ longer than the previous average. $\newline$ Expression for current average: $x + 85\%(x)$ $\newline$ = $x + 0.85x$
Calculate $85$ % Longer Expression: We found: Expression for current average is $x + 0.85x$ $\newline$ We know: Value for current average is $37$ minutes $\newline$ Set up an equation to find $x$ , the previous average. $\newline$ Equation for current average is $37 = x + 0.85x$ .
Set Up Equation for Previous Average: We found: $37 = x + 0.85x$ $\newline$ Solve for $x$ . $\newline$ $x + 0.85x = 37$ $\newline$ $1.85x = 37$ $\newline$ $x = \frac{37}{1.85}$ $\newline$ $x = 20$