Question

if each of the four letters in the sum below represents a different digit, which of the following cannot be a value of A?

AB
+ BA
------
CDC

1. 6
2. 5
3. 4
4. 3
5. 2

Answer 1

Answer 5.

Answer 2

\[\Huge \color\violet 5\]

Answer 3

how?

Answer 4

the answer isnt 5, you can have 56+ 65 = 121

Answer 5

No, as in choice 5.

Answer 6

The number AB can be represented as 10A+B
BA = 10B+A
Their sum is 10(A+B) + (A+B) = 11(A+B)
The only way for 11(A+B) to have an answer like CDC is is A + B = 11

Answer 7

So you try the answers out.
A = 6 means B = 5, 65+56 = 121
thats fine, they are all different digits.

You test them all, they will all be fine, except for A = 2
A = 2 means B = 9, we get 29+92 = 121, but D cant equal 2 because A is already 2.