This is a ridiculous question since a also cannot be 2. Even by your own logic c(2-a)=1 can never be true if a=2.
Carcass wrote:
OE
Given (a−b)(b−c)(a−c)=1 (equation 1)
Then (a−b)(b−c)=(a−c)
c(2-a)=1 (equation 2)
Since, the answer choices represent the values of a so let us put them in the eqn.2
and check which of them cannot be the value of a.
A. 0
If 𝑎 = 0, the eqn.2 reduces to
𝑐(2 − 0) = 1
i.e. 𝑐 =1/2
which is satisfying eqn.1
Hence, this can be the value of a.
B. 1
If 𝑎 = 1, the eqn.2 reduces to
𝑐 (2 − 1) = 1
i.e. 𝑐 = 1
If we put 𝑎 = 1 and 𝑐 = 1 in eqn.1 then we are getting denominator 0 which is possible.’
Hence, 𝑎 ≠ 1
Since this question has only one answer, so we do not need to check rest of
the answer choices.
Ans. (B)