Given, Total number of questions in part A=6 Total number of questions in part B=7 Pattern to choose 10 questions from 13 questions is 4 from part A and 6 from part B or 5 from part A and 5 from part B or 6 from part A and 4 from part B ∴ Total required number of ways =(6C4×7C6)+(6C5×7C5)+(6C6×7C4) =(15×7)+(6×21)+(1×39) =105+126+35=266