

Ex 5.2
Last updated at Dec. 13, 2024 by Teachoo
Transcript
Ex 5.2, 15 For what value of n, are the nth terms of two APs 63, 65, 67,… and 3, 10, 17, … equal Let’s find nth term of both APs 1st AP 63, 65, 67,… We know that an = a + (n – 1) d Here, a = 63 d = 65 – 63 = 2 Putting these in formula an = a + (n – 1) d = 63 + (n – 1) × 2 = 63 + 2n – 2 = 61 + 2n 2nd AP 3, 10, 17 … We know that an = a + (n – 1) d Here, a = 3 d = 10 – 3 = 7 Putting these in formula an = a + (n – 1) d = 3 + (n – 1) 7 = 3 + 7n – 7 = 7n – 4 Given that nth term of 1st AP = nth term of 2nd AP 61 + 2n = 7n – 4 61 + 4 = 7n – 2n 65 = 5n 65/5 = n 13 = n n = 13