9.
If n
terms of two AP's are 3n+8 and 7n+15, then the ratio of their 12 terms will
(D) 8/15
(A) 419
(B) 7/16
(C) 317
Answers
Answered by
1
Answer:
Step-by-step explanation:
AP 1 - 3n+8
Substituting values if n starting from n=1 the AP is defined as
11,14,17....
Here a =11
d =3
Now a12 for AP 1 is given as a+11d
= 11+ 11×3
=44
AP 2 - 7n+15
The AP is defined as
22,29,36....
a=22, d=7
a12 = a+11d
=22 + 11×7
=22+77
=99
Hence the ratio of 12th term is 44:99
=4:9 or 4/9
Similar questions