such that the numbers 
si 
are simultaneously prime .
.
Y by Mango247
A rectangular lawn is uniformly covered by grass of constant height. Andy’s mower cuts a strip of grass 
metre wide. He mows the lawn using the following pattern. First he mows the grass in the rectangular “ring” 
of width metre running around the edge of the lawn, then he mows the -metre-wide ring 
inside the first ring, then the -metre-wide ring 
inside , and so on until the entire lawn is mowed. Andy starts with an empty grass bag. After he mows the first three rings, the grass bag on his mower is exactly full, so he empties it. After he mows the next four rings, the grass bag is exactly full again. Find, in metres, all possible values of the perimeter of the lawn.
metre wide. He mows the lawn using the following pattern. First he mows the grass in the rectangular “ring” 
of width metre running around the edge of the lawn, then he mows the -metre-wide ring 
inside the first ring, then the -metre-wide ring 
inside , and so on until the entire lawn is mowed. Andy starts with an empty grass bag. After he mows the first three rings, the grass bag on his mower is exactly full, so he empties it. After he mows the next four rings, the grass bag is exactly full again. Find, in metres, all possible values of the perimeter of the lawn.This post has been edited 1 time. Last edited by parmenides51, Feb 25, 2021, 6:55 AM
,
is 
The area of the next 4 rings is
.
