Let the required parts of 24 be (a - d), a and (a + d) such that they are in AP.
Then (a - d) + a + (a + d) = 24
⇒ 3a = 24
⇒ a = 8
Also, (a - d).a.(a + d) = 440
⇒ a(a2 - d2) = 440
⇒ 8(64 -d2) = 440
⇒ d2 = 64 - 55 = 9
⇒ d = 3
Thus, a = 8 and d = 3
Hence, the required parts of 24 are (5, 8,11) or (11, 8, 5).