To the nearest $, which of these groups of numbers fall into three DIFFERENT equivalence classes?

A system calculates the amount of customs duty to be paid:

_ No duty is paid on goods value up to, and including, $2,000.

_ The next $8,000 is taxed at 10%.

_ The next $20,000 after that is taxed at 12%.

_ Any further amount after that is taxed at 17%.

To the nearest $, which of these groups of numbers fall into three DIFFERENT equivalence classes?
A . $20,000 $20,001 $30,001
B . $2,000 $2,001 $10,000
C . $2,000 $8,000 $20,000
D . $1,500 $2,000 $10,000

View Answer

Answer: C

Explanation:

Equivalence partitioning is a technique that divides the input domain of a system into partitions or classes that are expected to behave similarly or produce similar outputs2. A test case can cover one value from each partition, as it is assumed that all values in the same partition are equivalent for testing purposes2. In this question, the groups of numbers fall into different equivalence classes based on the amount of customs duty to be paid, as shown below:

Group                      Equivalence Classes

$20,000 $20,001 $30,001    No duty (up to $2,000), 10% duty ($2,001-$10,000), 12% duty ($10,001-$30,000), 17% duty (above $30,000)

$2,000 $2,001 $10,000      No duty (up to $2,000), 10% duty ($2,001-$10,000), 12% duty ($10,001-$30,000)

$2,000 $8,000 $20,000      No duty (up to $2,000), 10% duty ($2,001-$10,000), 12% duty ($10,001-$30,000)

$1,500 $2,000 $10,000      No duty (up to $2,000), 10% duty ($2,001-$10,000)