let the greatest number be a and remainder be x. And let the whole number result of the division be b, c and d. So we have
ab + x = 2447............(1)
ac + x = 3118...............(2)
ad + x = 6168.............(3)
Subtracting (2) - (1) gives:-
ac - ab = 671
a(c - b) =671
Now 671 = 61 * 11 so 61 could be the value of a
Checking:- 2447 / 61 = 40 remainder 7 , 3118 / 61 = 51 remainder 7
and 6168 / 61 = 101 remainder 7
Answer 61