Q7. Find the values of the letters in each of the following and give reasons for the steps involved.
The product of 6 & B gives a number whose unit digit is B again.
possible value of B = 0. 2 , 4, 6 or 8
If B = o then our product will be zero. hence this value of B is not possible.
If B = 2, then B x 6 = 12 . Carry for next step = 1.
6A + 1 = BB = 22
implies A = 21/6 = not any integer value hence this case is also not possible.
If B = 6 then B *6 = 36 and 3 will be carry for next step.
6A + 3 = BB = 66
implies A = 63/6 = not an integer value hence this case is also not possible.
If B = 8 then B * 6 = 48 and 4 will be carry for next step.
6A + 4 = BB = 88
implies A = 14 however A is a single digit number hence this case is also not possible.
If B = 4 then B*6 = 24 and 2 will be carry for next step.
6A + 2 = BB = 22
implies A = 7 .
Hence A = 7 and B = 4 is the correct answer.