Answer:
a₁ = 16
Step-by-step explanation:
The sum to infinity of a geometric series is
S ∞ = [tex]\frac{a_{1} }{1-r}[/tex]
where a₁ is the first term and r the common ratio , then
[tex]\frac{a_{1} }{1-0.2}[/tex] = 20
[tex]\frac{a_{1} }{0.8}[/tex] = 20 ( multiply both sides by 0.8 to clear the fraction )
a₁ = 0.8 × 20 = 16
