(b) The sum of n terms of two A.P.'s are in the ratio 5n + 4: 9n +the

1.	(b) The sum of n terms of two A.P.'s are in the ratio 5n + 4: 9n +the ratio of the 11th terms
Answer» We have two APs. AP1: The sum of the first 11 terms = 5n+4 or 511+4 = 59. The sum of the first 10 terms = 5n+4 or 510+4 = 54 The 11th term is 59–54 = 5. AP2: The sum of the first 11 terms = 9n+6 or 911+6 = 105 The sum of the first 10 terms = 9n+6 or 910+6 = 96 The 11th term is 105–96 = 9 SO the ratio of the 11th term of AP1 and AP2 = 5:9

(b) The sum of n terms of two A.P.'s are in the ratio 5n + 4: 9n +the ratio of the 11th terms

Answer»

We have two APs.

AP1: The sum of the first 11 terms = 5n+4 or 5*11+4 = 59.

The sum of the first 10 terms = 5n+4 or 5*10+4 = 54

The 11th term is 59–54 = 5.

AP2: The sum of the first 11 terms = 9n+6 or 9*11+6 = 105

The sum of the first 10 terms = 9n+6 or 9*10+6 = 96

The 11th term is 105–96 = 9

SO the ratio of the 11th term of AP1 and AP2 = 5:9