Question

the length breadth and height of a hall are 5m , 6m , 7m, respectively . the hall has one door of area 1m * 0.5m . find the cost of painting the halls (only the walls ) at the rate of Rs. 90 sq. meter

Answer 1

area to be painted =2[(5*7)+(6*7)]-1*0.5
                              
                               =70+84-0.5
                               = 153.5
 cost of painting 1sq.m=90
                                     = 153.5*90
                                      =13815

Answer 2

area including door= 2 (l + b) *h= 2(5+6)*7 = 154 m2
area of door = 1*0.5 =0.5
area to be painted = 154- 0.5 = 153.5 m2 cost of painting = 153.5*90 = Rs. 13815