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# The length, breadth and height of a cuboidal reservoir is 7 m, 6 m and 15 m respectively. 8400 L of water is pumped out from the reservoir. Find the fall in the water level in the reservoir.

**Solution:**

The Area of the base of the cuboidal reservoir = 7 × 6 = 42 m²

The volume of water pumped out is 8400 litres of water.

Now we know that 1litre = 0.001 m³

Therefore 8400 litres = 8400 × 0.001 = 8.4m³

Therefore

Base Area × Fall in water level in the reservoir = Volume of water pumped out

42 × Fall in the water level of the reservoir = 8.4

Fall in the water level of the reservoir = 8.4/42 = 0.2 m

**✦ Try This:** The length, breadth and height of a cuboidal reservoir is 12 m, 8 m and 15 m respectively. 19,200 L of water is pumped out from the reservoir. Find the fall in the water level in the reservoir.

The Area of the base of the cuboidal reservoir = 12 × 8 = 96 m²

The volume of water pumped out is 19,200 litres of water.

Now we know that 1litre = 0.001 m³

Therefore 8400 litres = 19,200 × 0.001 = 19.2m³

Therefore

96 × Fall in the water level of the reservoir =19.2

Fall in the water level of the reservoir = 19.2/96 = 0.2 m

**☛ Also Check:** NCERT Solutions for Class 8 Maths Chapter 11

**NCERT Exemplar Class 8 Maths Chapter 11 Problem 116**

## The length, breadth and height of a cuboidal reservoir is 7 m, 6 m and 15 m respectively. 8400 L of water is pumped out from the reservoir. Find the fall in the water level in the reservoir.

**Summary:**

The length, breadth and height of a cuboidal reservoir is 7 m, 6 m and 15 m respectively. 8400 L of water is pumped out from the reservoir. The fall in the water level in the reservoir is 0.2 m

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