DECLARE @allowdups BIT = 0
DECLARE @uppermain INT = 50
DECLARE @lowermain INT = 1
DECLARE @upperbon INT = 11
DECLARE @lowerbon INT = 1
DECLARE @maincount INT = 5
DECLARE @bonuscount INT = 2
       
CREATE TABLE #MainNumberBoundaries
(
Number TINYINT,
UpperLimit DECIMAL (15, 10)
)

CREATE TABLE #BonusNumberBoundaries
(
Number TINYINT,
UpperLimit DECIMAL (15, 10)
)

INSERT #MainNumberBoundaries (Number, UpperLimit)

SELECT sv.Number, (1.0000000/(@uppermain + 1 - @lowermain) * (sv.Number + 1 - @lowermain)) AS UpperLimit
FROM master..spt_values sv
WHERE sv.Number <= @uppermain
AND sv.Number >= @lowermain
AND sv.type = 'P'

INSERT #BonusNumberBoundaries (Number, UpperLimit)

SELECT sv.Number, (1.0000000/(@upperbon + 1 - @lowerbon) * (sv.Number + 1 - @lowerbon)) AS UpperLimit
FROM master..spt_values sv
WHERE sv.Number <= @upperbon
AND sv.Number >= @lowerbon
AND sv.type = 'P'

CREATE TABLE #MainNumbersToOutput
(
Number TINYINT NOT NULL
)

WHILE (SELECT COUNT(*) FROM #MainNumbersToOutput) < @maincount
BEGIN
WITH MyNumber (Number)
AS 
(
SELECT TOP 1 nb.Number
FROM #MainNumberBoundaries nb
WHERE RAND() < nb.UpperLimit
ORDER BY nb.Number ASC
)

INSERT #MainNumbersToOutput
SELECT mn.Number
FROM MyNumber mn
WHERE @allowdups = 1
OR mn.Number NOT IN (SELECT Number FROM #MainNumbersToOutput)
END

CREATE TABLE #BonusNumbersToOutput
(
Number TINYINT NOT NULL
)

WHILE (SELECT COUNT(*) FROM #BonusNumbersToOutput) < @bonuscount
BEGIN
WITH MyNumber (Number)
AS 
(
SELECT TOP 1 nb.Number
FROM #BonusNumberBoundaries nb
WHERE RAND() < nb.UpperLimit
ORDER BY nb.Number ASC
)

INSERT #BonusNumbersToOutput
SELECT mn.Number
FROM MyNumber mn
WHERE @allowdups = 1
OR mn.Number NOT IN (SELECT Number FROM #BonusNumbersToOutput)
END

SELECT Number, 'M'
FROM #MainNumbersToOutput
UNION ALL
SELECT Number, 'B'
FROM #BonusNumbersToOutput

DROP TABLE #MainNumberBoundaries
DROP TABLE #BonusNumberBoundaries
DROP TABLE #MainNumbersToOutput
DROP TABLE #BonusNumbersToOutput