Bank ID number is 237(a4)18538 and has an illegible 4th digit.
Determine the value of a4.
They also give the check digit formula, so a9 = 7(a1) + 3(a2) + 9(a3) + 7(a4) + 3(a5) + 9(a6) + 7(a7) + 3(a8) (mod 10)
Bank ID number is 237(a4)18538 and has an illegible 4th digit.
Determine the value of a4.
They also give the check digit formula, so a9 = 7(a1) + 3(a2) + 9(a3) + 7(a4) + 3(a5) + 9(a6) + 7(a7) + 3(a8) (mod 10)
Hello, cassiopeia1289!
Bank ID number is: .$\displaystyle 237(a_4)18538$ and has an illegible 4th digit.
Determine the value of $\displaystyle a_4.$
They also give the check-digit formula:
. . $\displaystyle a_9 \:= \:7(a_1) + 3(a_2) + 9(a_3) + 7(a_4) + 3(a_5) + 9(a_6) + 7(a_7) + 3(a_8) \pmod{10}$
Using the check-digit formula:
. . $\displaystyle 8 \:=\:7(2) + 3(3) + 9(7) + 7(a_4) + 3(1) + 9(8) + 7(5) + 3(3) \pmod{10}$
. . $\displaystyle 8 \:=\:7(a_4) + 205 \pmod{10}$
We have: .$\displaystyle 7(a_4) \:=\:\text{-}197 \pmod{10}$
. . . . . . . .$\displaystyle 7(a_4) \:=\:3 \pmod{10}$
. . . . . . . . . $\displaystyle a_4 \:=\:9 $