need help on thid question! thanks for your time

You have been hired as a consultant to help optimize the marketing budget of a small start-up. They estimate that for every hour of Spoofify ad time they purchase they gain additional sales according to the following equation (where His the number of hours purchased) Sales = 750"Ln(H) Each sale contributes $12.50 to the profit of the firm. Each hour of Spookify advertising costs the firm $85. What is the optimal number of hours of advertising you recommend the firm to purchase? [Please give your response in hours to the second decimal, thus if you find the optimal to be H*=5.234645 hours then simply type 5.24]