Transcript If United States imports increased 20 percent and exports decreased 10 percent during a certain year, the ratio of imports to.

If United States imports increased 20 percent and exports decreased 10 percent
during a certain year, the ratio of imports to exports at the end of the year was how
many times the ratio at the beginning of the year?
a)
b)
Difficulty: Hard
c)
d)
e) 2
HINT
Since the imports increased by 20%, the end-of-year imports
were 120% of the original imports. Also, since the exports
decreased by 10%, the end-of-year exports were 90% of the
original exports.
If the original imports are represented by I and the original
exports by E, then the end-of-year imports and exports would
be represented by 1.20I and 0.90E, respectively.
B: 4/3
Explanation
Express What You Know in Mathematical Terms
Write the ratio of imports to exports as .
At the end of the year, imports were up by 20%. So the end-of-year imports can be
expressed as 100% of the start-of-year imports plus 20%, or 120% of I.
At the end of the year, exports were down by 10%. So the end-of-year exports can
be expressed as 100% of the start-of-year exports minus 10%, or 90% of E.
The ratio of imports to exports at the end of the year can be expressed as
.
This is equivalent to of .