If each edge of a cube is increased by 50%, find the percentage increase in Its surface area
Let the edge = a cm
So increase by 50 % = =
Total surface Area of original cube =
TSA of new cube =
Increase in area = =
Increase % = = 125%
How many cubes of 3cm edge can be cut out of a cube of 18cm edge
number of cubes=(18 x 18 x 18) / (3 x 3 x 3) = 216
A rectangular block 6 cm by 12 cm by 15 cm is cut up into an exact number of equal cubes. Find the least possible number of cubes.
Volume of the block = (6 x 12 x 15) = 1080
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) = 27
Number of cubes = = 40.
A cistern 6m long and 4 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:
Area of the wet surface = [2(lb + bh + lh) - lb]
= 2(bh + lh) + lb
= [2 (4 x 1.25 + 6 x 1.25) + 6 x 4]
The volume of a wall, 5 times as high as it is broad and 8 times as long as it is high, is 12.8 cu. meters. Find the breadth of the wall.
Let the breadth of the wall be x metres.
Then, Height = 5x metres and Length = 40x metres.
x * 5x * 40x = 12.8