Question
Question: If \(\frac{n}{7}\), n ÎN is a non-terminating and is a recurring decimal rational number. After deci...
If 7n, n ÎN is a non-terminating and is a recurring decimal rational number. After decimal at some stage, digits start repeating in groups continuously. If smallest such group has r digits, then –
A
Maximum value of r is 3
B
Maximum value of r is 7
C
Maximum value of r is 6
D
Maximum value of r is 9
Answer
Maximum value of r is 6
Explanation
Solution
71 = 0.142857
71 = 0.142857142857
Clearly these are 6 digits in repeating group
A repeating group can not contain 7 or more than 7 digits because the divisor is 7.
Hence maximum value of r is 6.