69) What is the total surface area of cube having each edge of length 20?

70) At room temperature plain carbon steel contains

71) The LCM of 2, 3, 4 is

72) Simple interest for Rs. 2000 in two years at an interest rate of 5 % is

73) A ladder of 5 m length is kept leaning against a wall such that its tip is along the top of the wall. The lower end of t he ladder is 4 m away from the base of the wall. Then the height of the wall is