Question
Consider an infinite geometric series with first term a and common ratio r. If its sum is 4 and the second term is 3 4 , then:
BITSAT
Mathematics
Sequences and Series
2021
BITSAT 2021
BITSAT Mathematics Question (2021) — Solution
Options
- A. a= 4 7 , r= 3 7
- B. a=2, r= 3 8
- C. a= 3 2 , r= 1 2
- D. a=3, r= 1 4
Answer
D. a=3, r= 1 4
Step-by-step solution
Since, sum =4 and second term = 3 4 a 1-r =4, and a r= 3 4 a 1- 3 4 a =4 (a-1)(a-3)=0 a=1 or a=3 array l a 1- 3 4 a =4 \\ (a-1)(a-3)=0 \\ a=1 or a=3 array
Related: Mathematics — Sequences and Series · All PYQ Banks