Question 150
a) Four positive integers $a$, $b$, $c$, $d$ satisfy the condition: each of the numbers $ab$, $bc$, $cd$, $da$ is a perfect cube. Are all the numbers $a$, $b$, $c$, $d$ perfect cubes?
b) Five positive integers $a$, $b$, $c$, $d$, $e$ satisfy the condition: each of the numbers $ab$, $bc$, $cd$, $de$, $ea$ is a perfect cube. Are all the numbers $a$, $b$, $c$, $d$, $e$ perfect cubes?
b) Five positive integers $a$, $b$, $c$, $d$, $e$ satisfy the condition: each of the numbers $ab$, $bc$, $cd$, $de$, $ea$ is a perfect cube. Are all the numbers $a$, $b$, $c$, $d$, $e$ perfect cubes?