If a – b : b – c : c – d = 1 : 2 : 3, then a + d : c = ?

Let d = 1

ATQ,

if d= 1,  then  c = 4 (because c - d = 3)

if c= 4,  then  b = 6 (because b - c = 2)

if b= 6,  then  a = 7 (because a - b = 1)

Now,

\(\frac{a + d}{c}\) = \(\frac{7 + 1}{4}\) = \(\frac{2}{1}\) = 2 : 1