Question 92297
let t=Tom so 480-t=David ... (t/6)+((480-t)/9)=72 ... multiplying by 9 and 6 gives 9t+(6*480)-6t=72*9*6


9t+2880-6t=3888 ... 3t=1008 ... t=336 ... 480-t=144


Tom's columns=336/6=56 ... David's columns=144/9=16