Question

​ Without using long division, show that the rational number 21/1120 has a terminating decimal expansion . Also find its decimal expansion

Answer 1

go through the solution.

Answer 2

21/1120= 3×7/7×160

=3/160

=3/2^5×5^1

=p/q

Therefore the given number is terminating decimal.

=3/2^5×5^1

=3×5^4/2^5×5^4×5^1

=3×5^4/2^5×5^5

=1875/(10)^5

=1875/100000

=0.01875