Question

One indicator of a declining economy is a continued decline in birth rates. In 2010, birth rates in Europe were at an all-time low, with the average number of children that a women has in her lifetimes at well below two. In the figure, $f\left(t\right)$ represents birth rates for Portugal between 1960 and 2010, and $g\left(t\right)$ represents birth rates in Slovakia for the same time period. For which value(s) of $t$ is $f\left(t\right)>g\left(t\right)$?

• A. $1960<t<1980$ only
• B. $1980<t<2000$ only
• C. $1960<t<1980$ and $1990<t<2000$
• D. $1960<t<1980$ and $2000<t<2010$

Answer 1

The correct option is D $1960<t<1980$ and $2000<t<2010$

The statement $f\left(t\right)>g\left(t\right)$ translates to "Where is $f\left(t\right)$ above $g\left(t\right)$?
The solid curve represents $f$ and the dashed curve represents $g$, so $f\left(t\right)>g\left(t\right)$ between the years $1960$ and $1980$ and again between the years $2000$ and $2010$.
Look at the option and see the time intervals: $1960<t<1980$ and $2000<t<2010$ is the answer.