The equation \( (2m+n)+(2n+m)=27 \) just adds up to \( 3m+3n=27 \), so \( m+n=9 \). Since \( m \) and \( n \) must both be positive whole numbers, pushing \( m \) as high as possible means pushing \( n \) as low as possible, and the smallest positive integer \( n \) can be is 1. That forces \( m=8 \), the largest \( m \) can get. Plugging into \( 2m-3 \) gives \( 2(8)-3=13 \), so the maximum value of \( (2m-3) \) is 13.