Question

A rectangular tank is 25m long 1200cm wide and 6000 mm deep . The tank is open at the top.the cost of plastering the inside of its walls and bottom floor at R26 per square metre is

Answer 1

19344 rupees

Explanation:

Given:

Length of a rectangular tank (l) = 25 m

Breadth of a rectangular tank (b) = 1200 cm

Height of a rectangular tank (h) = 6000 mm

To find: cost of plastering the inside of its walls and bottom floor at Rs 26 per square metre

Solution:

Surface area of walls and bottom floor of the rectangular tank =
`lb+2(bh+hl)`

Use
`1 m = 100 \,cm\,,\,1m=1000\,mm`

`l=25\,m\\b=1200\,cm=12\,m\\h=6000\,mm=6\,m`

Surface area of walls and bottom floor of the rectangular tank =
`25(12)+2[(12)(6)+(6)(25)]=300+2(72+150)=300+444=744\,m^2`

Cost of plastering the inside of its walls and bottom floor at Rs 26 per square metre = 744 × 26 = 19344 rupees