Question

If p/q is a rational numbrr. What is the condition on q so that the decimal representation of p/q is terminating

Answer 1

q should be in the form of 2^n ×5^n

for exaple q=20

then,

q= 2^2×5^1

so the decimal will be terminating

Answer 2

for a decimal expansion to be terminating it's decimal expansion should be of form
${2}^{m} \times {5}^{n}$