R = 16 according to the problem, so the total amount of income will be: $20*16 + $15*(40 - 16) = $320 + <span>$15*(24) = </span>$320 + <span>$360 = $680 that is the income, but the expenses are $275 so the total revenue is the subtraction of those two total revenue = $680 - $275 = $405</span>
