its 4 lawns per 6 hours so to make it easier divide both sides by 2, then 2 lawns per 3 hours. So if he lawn 15 hours then 15/3(2) is 5(2) then he can mow 10 hours per 15 hours
Tim can mow 10 lawns in 15 hours, given his mowing rate. This was calculated based on the rate of 4 lawns in 6 hours, which simplifies to 2/3 of a lawn per hour. When multiplied by 15 hours, he can complete 10 lawns.
;