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The sum till infinity of a Geometric Progression, with first term 16 and common ratio $$r$$, is 48. Find the sum till infinity of another GP with first term 76 and a common ratio of $$\left(r-\dfrac{1}{6}\right)$$.
Given that the first term of GP is 16 and sum till infinity is 24
So, $$S_∞=\dfrac{a}{1-r}$$, where $$a$$ is the first term and $$r$$ is the common ratio.
$$S_∞=\dfrac{16}{1-r}=48$$
$$1-r=\dfrac{16}{48}=\dfrac{1}{3}$$
or, $$r=\dfrac{2}{3}$$
Now, we have to find sum till infinity of another GP whose first term is 76 and common ratio is $$r_1=\left(r-\dfrac{1}{6}\right)=\dfrac{2}{3}-\dfrac{1}{6}=\dfrac{1}{2}$$
$$S_∞=\dfrac{76}{1-\dfrac{1}{2}}$$
$$S_∞=152$$
Hence, the answer is 152
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