NB: The Logic involves the subtraction of 1 from the first number and multiplying the number after the alphabet A to get the result.
Note 4A5 = 15 , 6A7 = 35 and 9A1 = 8. Use the logic to find the missing number in the question. Answer: the pattern is to subtract 1 from the number proceeding A and multiply the result by the number after A to get the result on the R.H.S