Question

Four piece of 20 kg each & 2 pieces of 25 kg each are moulded from cast iron and if 12% of cast iron is wasted the total cast iron is required

Answer 1

According to question

Number of 20 kg peices = 4 pieces
Thus

Total wt of 4 pieces = 4 * 20 = 80 Kg

Similarly
Total wt. of 25 kg pieces = 25 * 2 = 50 Kg

Thus total wt formed = 80 + 50 = 130 Kg
So

when 12 % of this is wasted
12% of  130 = 130 * 12/100
                    = 15.6 Kg

Thus left amount of casted iron = 130 - 15.6
                                                  = 114.4 Kg

Answer 2

Four pieaces of 20kg each and 2pieaces of 25kg each are moulded from cast iron and if 12%of cast iron is wanted the total cast iron required is