A certain evaporator is boiling a solution that deposits calcium sulphate scale. after 4 hr and 10 min of operation, the u is 545 $%& '( ∙ *%+ ∙ ℉ and after 12 hr and 30 min, it was 430. what would the coefficient be at the start of operation?a. 800b. 652c. 400d. 300