Question

Let a, b, c be three numbers between 2 and 18 such that their sum is 25. if 2, a, b are in
a.p. and b, c, 18 are in g.p., then 'c' equal:

Answer 1

2 < a, b, c, < 18 a + b + c = 25 ……. (1)

2, a, b are AP ⇒ 2a = b + 2

⇒ 2a – b = 2 …….. (2)

b, c, 18 are in GP ⇒ c2 = 18b …… (3)

From (2) ⇒ a = b +2/2

(1) ⇒ b + 2/2 + b + c = 25 ⇒ 3b = 48 – 2c

(3) ⇒ c2 = 6 (48 – 2c) ⇒ c2 + 12c – 288 = 0

⇒ c = 12, - 24 (rejected)

⇒ a = 5, b = 8, c = 12

Answer 2

Answer:

yes it is correct