Question

A tank open at the top is made of iron sheet 4 m wide. If the dimensions of the tank are 12 m × 8 m × 6 m, find the cost of iron sheet at Rs 17.50 per metre.

Answer 1

\[\text { An open iron tank of dimensions 12 m } \times 8 m \times 6 m is \text { to be made .  }\]

\[\text { Surface area of the open tank = (area of the base) + (total area of the 4 walls) }\]

\[ = (12 \times 8) + 2 \times (8 \times 6 + 12 \times 6)\]

\[ = (96) + 2 \times (48 + 72)\]

\[ = 336 m^2 \]

\[\text { Also, it is given that the cost of the iron sheet that is 4 m wide is Rs 17 . 50 per metre } . \]

\[\text { i . e . , the area of the iron sheet = 1 m  }\times 4 m = 4 m^2 \]

\[\text { So, the cost of 4  }m^2 \text { of iron sheet = Rs 17 . 50  }\]

\[ \therefore \text { The cost of iron sheet required to an iron tank of surface area 336 } m^2 = 336 \times \frac{17 . 50}{4} = Rs 1470\]