I wasn't sure if you were looking for all combinations of Customers that meet that percentage or just starting with the min number or.???

At anyrate, I just used a simple running total solution to get some results. Hopefully, it'll help:DECLARE @Temp table (customer varchar(15),number int)

insert into @Temp select'A',10

insert into @Temp select'B',20

insert into @Temp select'C',17

insert into @Temp select'D',18

insert into @Temp select'E',30

insert into @Temp select'F',40

insert into @Temp select'G',10

insert into @Temp select'H',20

insert into @Temp select'I',17

insert into @Temp select'J',18

insert into @Temp select'K',30

insert into @Temp select'L',40

DECLARE @Sum INT

SELECT @Sum = SUM(number)

FROM @Temp

DECLARE @Percent FLOAT

SET @Percent = @Sum * .6

SELECT

customer, Number, RunningTotal

FROM

(

SELECT

customer,

number,

(

SELECT SUM(Number)

FROM

(

SELECT *,ROW_NUMBER() OVER (ORDER BY Number, Customer) AS RowNum

FROM @Temp

) AS A

WHERE RowNum <= T.RowNum

) AS RunningTotal

FROM

(SELECT *,ROW_NUMBER() OVER (ORDER BY Number, Customer) AS RowNum FROM @Temp) T

) AS D

WHERE

RunningTotal <= @Percent -- Could add on some sort of varience if needed

ORDER BY

RunningTotal