The exports of goods of a country, \( G = G(t) \), has a growth rate of \( a/t \), and its exports of services, \( S = S(t) \), has a growth rate of \( b/t \). What is the growth rate of its total exports \( X \)?
Show Hint
The growth rate of total exports is the sum of the individual growth rates of goods and services.
Let the total exports \( X \) be the sum of exports of goods and services, i.e.,
\[
X = G + S
\]
We are given that:
- The growth rate of exports of goods is \( a/t \)
- The growth rate of exports of services is \( b/t \)
The growth rate of total exports \( X \) is simply the sum of the growth rates of goods and services. Therefore, the growth rate of total exports is:
\[
\frac{a}{t} + \frac{b}{t}
\]
Final Answer:
\[
\boxed{\frac{a}{t} + \frac{b}{t}}
\]