Maths 12 14 17 13 8 14 21 13 4 ?

12 14 17 13 8 14 21 13 4 ? - - 12 14 17 13 8 14 21 13 4 ?  Maths in hindi,  number series  13 question answers in hindi pdf   14 questions in hindi, Know About 2 Maths online test Maths MCQS Online Coaching in hindi quiz book     15