The mean of marks secured by 60 students in division A of class X is 66, 45 students of division B is 62 and that of 75 students of division C is 60. Find the mean of marks of the students of three divisions of Class X.
If a merchant offers a discount of 40% on the list price, then he makes a loss of 10%. What % profit or % loss will he make if he sells at a discount of 20% of the list price?