Question

Jim sent 5 pieces of mail in September, 15 pieces of mail in October, 45 pieces of mail in November, and 135 pieces of mail in December. If this pattern continues, how many pieces of mail will Jim send in January?

Answer 1

$\text{A series of numbers }5,15,45,135\text{ is a geometric progression}$

$\text{ with common ratio } 3$

$5,5*3,15*3,45*3$

$\text{It is logical to assume that there will be three times more letters in January}$

$\text{than in December }135*3= 405$

Answer: 405 pieces