WBJEE · Maths · Sequences and Series
If sum of an infinite geometric series is \(\frac{4}{5}\) and its 1 st term is \(\frac{3}{4}\), then its common ratio is
- A \(\frac{7}{16}\)
- B \(\frac{9}{16}\)
- C \(\frac{1}{9}\)
- D \(\frac{7}{9}\)
Answer & Solution
Correct Answer
(A) \(\frac{7}{16}\)
Step-by-step Solution
Detailed explanation
Hints: \(\frac{\mathrm{a}}{1-\mathrm{r}}=\frac{4}{3} \quad\) Then \(\frac{\frac{3}{4}}{1-\mathrm{r}}=\frac{4}{3} \Rightarrow \mathrm{r}=1-\frac{9}{16}=\frac{7}{16}\)
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