Question

A door 2m*1m is fixed on a wall.The wall is 8.5 long and 2m high.Find the cost of whitewashing the wall ₹40 per square meter​. ​

Answer 1

`600\ rupees`

Explanation:

`We\ are\ given:\\Dimensions\ of\ the\ door=2m *1m\\Dimensions\ of\ the\ wall=8.5m*2m\\Cost\ of\ whitewashing\ of\ 1m^2=40\ rupees\\Hence,\\First\ lets\ consider\ the\ wall:\\Area\ of\ a\ rectangle= Length*Width\\Here,\\Length\ of\ the\ wall=8.5\ m\\Width\ of\ the\ wall=2\ m[As\ here\ width\ and\ height\ are\ the\ same\ thing]\\Hence,\\Area\ of\ the\ wall=8.5*2=17\ m^2`

`Now,\\Lets\ consider\ the\ door:\\As\ we\ know\ that,\\Area\ of\ a\ rectangle=Length*Width\\Here,\\Length\ of\ the\ door=2m\\Width\ of\ the\ door=1\ m\\Hence,\\Area\ of\ the\ door=2*1=2m^2\\\\Now,\\The\ area\ to\ be\ whitewashed=Area\ of\ the\ wall-Area\of\ the\ door\\Hence,\\The\ area\ to\ be\ whitewashed=17-2=15\ m^2\\\\As\ we\ know\ that,\\Cost\ of\ whitewashing\ 1\ m^2\ of\ the\ wall= 40\ rupees\\Hence,\\`

`Cost\ of\ whitewashing\ the\ whole\ wall=Area\ of\ the\ wall\ to\ be\\ whitewashed*Rate\ of\ whitewashing\ per\ m^2\\Hence,\\Cost\ of\ whitewashing\ the\ whole\ wall=15*40=600\ rupees`