There is a cuboidal tank whose length, breadth and height are 15 m, 28

1.	There is a cuboidal tank whose length, breadth and height are 15 m, 28 dm and 6 m respectively. 75% of the tank's water need to be pumped out, find the total time taken (in hours) to pump out the required amount of water through a tap that can pump out 7 litres of water per minute.1. 3002. 3503. 4004. 450
Answer» Correct Answer - Option 4 : 450 Given : Length, breadth and height of the tank are respectively 15 m, 28 dm and 6 m 75% of the whole volume need to be taken out of the tank Outlet tap can pump out 7 litres of water per minute Formula used : The total volume of the cuboid = length × breadth × height Total time taken to pump out water = Total volume/Water thrown out per unit time Calculations : Volume of the cuboid = 15 × 2.8 × 6 (1 dm = (1/10) m) ⇒ 252 m³or 252000 litres (1 m3 = 1000 litres) Now 75% of the total volume = 75% of 252 m³ ⇒ 189 m³ or 189000 litres Total time taken to pump out 75% of the water = 189000/7 ⇒ 27000 minutes Total time in hours = (1/60) × 27000 ⇒ 450 hours ∴ total time taken to pump out 75% of the water is 450 hours

There is a cuboidal tank whose length, breadth and height are 15 m, 28 dm and 6 m respectively. 75% of the tank's water need to be pumped out, find the total time taken (in hours) to pump out the required amount of water through a tap that can pump out 7 litres of water per minute.1. 3002. 3503. 4004. 450

Answer» Correct Answer - Option 4 : 450

Given :

Length, breadth and height of the tank are respectively 15 m, 28 dm and 6 m

75% of the whole volume need to be taken out of the tank

Outlet tap can pump out 7 litres of water per minute

Formula used :

The total volume of the cuboid = length × breadth × height

Total time taken to pump out water = Total volume/Water thrown out per unit time

Calculations :

Volume of the cuboid = 15 × 2.8 × 6 (1 dm = (1/10) m)

⇒ 252 m³or 252000 litres (1 m3 = 1000 litres)

Now 75% of the total volume = 75% of 252 m³

⇒ 189 m³ or 189000 litres

Total time taken to pump out 75% of the water = 189000/7

⇒ 27000 minutes

Total time in hours = (1/60) × 27000

⇒ 450 hours

∴ total time taken to pump out 75% of the water is 450 hours