MYSQL QUERY HELP GROUP BY

[Praba Karan]

sold_week_no, sold_by_l1,sold_by_l2,sold_by_l3
1 101 103 105
1 105 103 101
2 103 101 105
3 105 101 103
3 101 103 102

Now How do i get reult of

SOLDWEEK ID COUNT
1 101 2
1 103 2
1 105 2
2 103 1
2 101 1
2 105 1
3 101 2
3 103 2
3 105 2

I donot know how to exactly use group by class. Please how to I proceed

Thanks in advance
Sincerly
Prabakar