Question

find the number abcd such that when multipled by 4 gives dcba

Answer 1

4abcd=dcba
4a=d. 4b=c. 4c=b. 4d=a
a=0. b=0. c=0. d=0

Answer 2

4a=d. b=c
=>a=0. =>b is any real no.
c=b
=>c is any real no.
d=a
=>d=0