Question

plz give the correct answer to Que. no. 14

Answer 1

Answer:

Step-by-step explanation:

n = number of terms = 37

middle term = (n+1) / 2 = 38/2  = 19th term

∴Middle most terms = 18th term 19th term 20th term

⇒225 = a + (18-1)d + a + (19-1)d + a + (20-1)d

⇒225 = 3a + 17d +18d +19d

⇒225 = 3a + 54d

∴ 3a = 225 - 54d

last three terms = 37th 36th 35th

⇒429 = a + (37-1)d + a + (36-1)d + a + (35-1)d

⇒429 = 3a + 36d + 35d + 34d

⇒429 = 3a + 105d

∴ 3a = 429 - 105d

∴225 - 54d = 429 - 105d

429 - 225 = 105d - 54d

204 = 51d

d = 4

∴ a = 3 (by substituting value of d in equation

∴ AP = 3, 7, ....144, 147