Question 387760
{{{140 + 70 + 35 + .....}}}............since {{{70=(1/2)140}}} and {{{35=(1/4)140}}} you will have:


=140(1+1/2+1/4+....+)

= 140 * Sum [(1/2)^n] (n -> infinity)

= 140 * 1/(1 - 1/2).........(Property of infinite geometric series for {{{0 < r < 1)}}}

= 140 * 2

= 280