Question

Which of the following rational number is in the standard form?

(a) \(\frac{16}{21}\)

(b) \(\frac{16}{24}\)

(c) \(\frac{21}{15}\)

(d) \(\frac{-21}{56}\)

The question was asked in a national level competition.

This is a very interesting question from Properties of Rational Numbers in chapter Rational Numbers of Mathematics – Class 8

Answer 1

Correct choice is (a) \(\frac{16}{21}\)

The best I can explain: A rational number is said to be in it’s standard form when the numbers cannot be further reduced.

Here, we can see that the options other than the option \(\frac{16}{21}\) can be reduced.

When \(\frac{16}{24}\) is reduced, we get \(\frac{2}{3}\)… Standard Form.

When \(\frac{21}{15}\) is reduced, we get \(\frac{7}{5}\)… Standard Form.

When \(\frac{-21}{56}\) is reduced, we get \(\frac{-3}{8}\)… Standard Form.