Question

Which of the following is not a terminating decimal?

Options

• `11/80`

• `63/35`

• `5/11`

• `17/1250`

Answer 1

`bb(5/11)`

Explanation:

To determine which of the given fractions is not a terminating decimal, recall this rule:

A fraction in its simplest form will have a terminating decimal only if the denominator (after simplification) has only 2 and/or 5 as prime factors.

Let’s check each option:

a. `11/80`

80 = 2⁴ × 5

Only prime factors are 2 and 5 

So this is a terminating decimal.

b. `63/35`

Simplify: `63/35 = 9/5`

Only prime factors are 5

So this is a terminating decimal.

c. `5/11`

Only prime factors are 2 and 5 

So this is a non-terminating decimal.

d. `17/1250`

1250 = 2 × 5⁴

Only prime factors are 2 and 5 

So this is a terminating decimal.