Q15. The volume of a rectangular block of stone is 10368 dm2. Its dime

1.	Q15. The volume of a rectangular block of stone is 10368 dm2. Its dimensions are in the ratio of 3:2:1. If itsentire surface is polished at 2 paisa per dm2, then find the cost incurred to polish.
Answer» The dimensions are 3x : 2x : x The volume is { 6x }^{ 3 }=10368 So, x is { 6x }^{ 3 }=10368 therefore x= 12 So, the dimensions are 36cm, 24cm and 12 cm respectively. The surface area is 2(36×24+ 24×12+ 12×36)=3168 cm^2 Total cost is 3168 ×0.02=Rs. 63.36

Q15. The volume of a rectangular block of stone is 10368 dm2. Its dimensions are in the ratio of 3:2:1. If itsentire surface is polished at 2 paisa per dm2, then find the cost incurred to polish.

Answer»

The dimensions are 3x : 2x : x

The volume is { 6x }^{ 3 }=10368

So, x is { 6x }^{ 3 }=10368

therefore x= 12

So, the dimensions are 36cm, 24cm and 12 cm respectively.

The surface area is 2(36×24+ 24×12+ 12×36)=3168 cm^2

Total cost is 3168 ×0.02=Rs. 63.36