Question

Owing to an innovative rural public health program, infant mortality in Senegal, West Africa, is being reduced at a rate of 10% per year. How long will it take for infant mortality to be reduced by 50%?

Answer 1

8.42

Answer 2

100%-10%=90% 90/100= .9
Each year there is 90% increase or .9

We are looking for when the mortality rate is down to 50% or .5

The equation is .9^x=.5
Change into Logarithmic form:

log(base .9).5=x
Change of base formula:
log.5/log.9=x
x=6.5788 or 6.57 years