DHAR
When a positive integer n is divided by 100, the remainder is the same as the quotient but when n is divided by 14, the remainder is 0.How many distinct integer values can n take if n is more than 1000 and less than 9999?
A.5
B.6
C.7
D.8
E.More than 8
Solution:
If we let the quotient be q when n is divided by 100, we have n = 100q + q (since the remainder is the same as the quotient). If we let the quotient be u when n is divided by 14, we have n = 14u (since the reminder is 0). Therefore, we have:
100q + q = 14u
101q = 14u
Since 101 and 14 are relatively prime, q must be a multiple of 14 and u must be a multiple of 101. Since u is a multiple of a larger number, let’s check the possible values of u and hence the possible values of n (keep in mind that n = 14u and 1000 < n < 9999):
If u = 101, n = 14 x 101 = 1414.
If u = 202, n = 14 x 202 = 2828.
If u = 303, n = 14 x 303 = 4242.
If u = 404, n = 14 x 404 = 5656.
If u = 505, n = 14 x 505 = 7070.
If u = 606, n = 14 x 606 = 8484.
If u = 707, n = 14 x 707 = 9898.
We see that there are 7 possible values of n (notice that if u = 808, n will be greater than 9999).
Answer: C