Q24 of 128 Page 25

Which of the following numbers have terminating decimal expansion and why?

Here, the denominator is 49.

49 = 7 × 7 × 2⁰ × 5⁰

We can see that that 49 contains 7 as its prime factors other than 2 and 5.

Also, 132 = 2 × 2 × 3 × 11

So, g. c. d(132, 49) = 1

Therefore,
does not have a terminating decimal expansion

Which of the following numbers have terminating decimal expansion and why?

Find the square root of the following in the form of a binomial surd :