Question 620400

The equation R=-0.028t+20.8 can be used to predict the world record in the 200-m dash, where R is the record in seconds and t is the number of years since 1920. In what year will the record be 18.0 seconds?


R(t) = - 0.028t + 20.8
18 = - 0.028t + 20.8
0.028t = 20.8 – 18
0.028t = 2.8
t, or time for the record to be 18 secs = {{{2.8/0.028}}}, or 100 years


100 years from the year 1920 = the {{{highlight_green(year_2020)}}}


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