The number of the members of a club is more than 50 and less than 80. When 5 people sit at a table, other people exactly divided to 8-people groups (8 people sit at a table) or 7-people groups (7 people sit at a table). If the members are divided to 9-people groups, how many people will be left?
Choose the correct choice from the following answers
A) 4  B) 5  C) 6  D) 7  E) 8
The number of members is 7k+5 = 8j+5   The only number in this range which satisfies this is 61.   61/9 = 6(9) + 7   The answer is 7.
<result>D</result>
The number of the members of a club is more than 50 and less than 80. When 5 people sit at a table, other people exactly divided to 8-people groups (8 people sit at a table) or 7-people groups (7 people sit at a table). If the members are divided to 9-people groups, how many people will be left?