Q9 of 24 Page 236

A box open at the top has its outer dimensions 10 cm, 9 cm, and 2.5 cm and its thickness is 0.5 cm. Find the volume of the metal.

Given,


Outer length (L) = 10 cm


Outer breadth (B) = 9 cm


Outer height (H) = 2.5 cm


Outer volume = L × B × H = 10 × 9 × 2.5 = 225 cm3


Thickness (t) = 0.5 cm


Inner dimensions:


l = L – 2t = 10 - 2(0.5) = 9 cm


b = B – 2t = 9 – 1 = 8 cm


h = H – t = 2.5 - 0.5 = 2 cm


(Since it is Open at the top)


Inner volume = lbh = 9 × 8 × 2 = 144 cm3


Volume of metal = Outer volume - Inner volume


= 225 - 144


= 81cm3


So, the volume of metal is 81cm3


More from this chapter

All 24 →
7

The length breadth and height of the room 5m, 4m, and 3m respectively. Find the cost of washing the inner of the room and ceiling at the rate of Rs. 50 per square metre.

 8

The length breadth and height of a cuboidal box is 2 meters 10cm, 1m and 80cm. Find the area of the canvas.

 10

The length breadth and height of the cuboidal tank are 150cm, 120cm and 110cm respectively. The tank has 129600cm3 of water in it. 100 porous bricks each having dimensions 20cm × 10cm × 10cm and are placed in the tank. Calculate the raise in the water level of the tank. If each brick absorbs 1/10 of its own volume.

 11

The inner diameter of a metallic tube of density 7g/cm3 is 2.5 cm. The thickness of the tube is 0.29 cm. Find the weight of the tube if it is of length 30 cm.