Use SUM function with Group By clause.
CREATE TABLE #Products(Product VARCHAR(20),Product_Rate INT,Ex_rate INT)
INSERT INTO #Products VALUES('Aaa',100,99),('Aaa',50,98)
SELECT Product,SUM(Product_Rate) tot_qty,SUM(Product_Rate)*MAX(ex_Rate) tot_amt
FROM #Products
GROUP BY Product
DROP TABLE #Products
Output
Product tot_qty tot_amt
Aaa 150 14850