UPSC Civil Services 2015 Prelims General Studies Paper II

ABC × DEED = ABCABC
We know that, when we write any Number in form of ABCABC then that number must be divisible by 13 , 11 and 7 or ABCABC is multiple of 1001
So, 1001 = DEED
1001 = 13 × 11 × 7
ABC × DEED = ABC ABC
⇒ ABC × 1001 = ABC ABC
On comparing
D = 1, E = 0