Question

The sum of n term of an AP is in ratio 5n+4:9n+6.find the ratio of their 18th term

Answer 1

Answer:

Step-by-step explanation:

Sn= 5n + 4 : 9n + 6

ANS let n= 18 ,

S18 = 5×18 + 4 : 9 × 18 +6

=94:168(divide by 2)

=47:84 (divide by 7)

=7:12

Therefore the ration of its 18th term is 7:12