Surface Area MCQ Question with Answer

Let the breadth of the wall be x meters.
Then, Height = 5x meters and Length = 40x meters.

                     x * 5x * 40x = 12.8 
                    x³=12.8/200 = 128/2000 = 64/1000

                 
                     So, x = (4/10) m =((4/10)*100)cm = 40 cm

Volume of the wall = (2400 x 800 x 60) cu. cm
Volume of bricks = 90% of the volume of the wall

                         =((90/100)*2400 *800 * 60)cu.cm.

        Volume of 1 brick = (24 x 12 x 8) cu. cm.

 Number of bricks=(90/100)*(2400*800*60)/(24*12*8)=45000.

Volume required in the tank = (200 x 150 x 2) m³ = 60000 m³
Length of water column flown in1 min =(20*1000)/60 m =1000/
 Volume flown per minute = 1.5 * 1.25 * (1000/3) m³ = 625 m³.

 Required time = (60000/625)min = 96min

Volume of the metal used in the box = External Volume - Internal Volume

                                                     = [(50 * 40 * 23) - (44 * 34 * 20)]cm³

                                                      = 16080 cm³

 Weight of the metal =((16080*0.5)/1000) kg = 8.04 kg.

6a² = 1734 , a² = 289 , a = 17 cm.

 Volume = a³ = (17)³ cm³ = 4913 cm³.

      Volume of the block = (6 x 12 x 15) cm³ = 1080 cm³.

       Side of the largest cube = H.C.F. of 6 cm, 12 cm, 15 cm = 3 cm.

       Volume of this cube = (3 x 3 x 3) cm³ = 27 cm³.

       Number of cubes = 1080/27 = 40.