Question 571138
year		Record time					
1920		45.4	seconds				
1970		44.4	seconds				
Difference							
50		-1					
rate of reduction per year =-1	/50	=	-0.02
							
R(t)=	45.4-0.020t 			
							
2003	t=83					
							
R(t)=	45.4	+	-0.020	*	83		
							
R (83)=	43.74	seconds		

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R(t)=	45.4-0.02t 
43.5=45.4-0.02t
45.4-43.5=0.02t
1.9=0.02t
t= 1.9/0.02
t=95 years

1920 +95 = 2015

year 2015  it will bve 43.5 seconds