Question 377863
In 1920 a record for a race was 45.3 seconds.
In 1940 it was 44.7 seconds.
decrease per year = (45.3-44.7) /20
=0.6/20
=0.03 per year.
R(t) = 45.3-0.03t
......
In 2003
-------------
R(83)= 45.5-0.03*83
R(83)=45.5 -2.49
R(83)=42.81
In 2003 the record will be 42.81 seconds.
plug t=86 for 2006
..
3.) 42.5 = 45.5 -0.03t
0.03t=45.5-42.5
0.03 t = 3
t = 3/0.03
t=100 
Add 100 years to 1920= 2020
In 2020 the recoed will be 42.5 seconds
m.ananth@hotmail.ca