Question 111

The average weight of 89 notebooks in a box is 8.9 kg. When a new notebook is added, its average is 9 kilograms. Find the weight of the new notebook. (In kg)

Solution

Average weight of 89 Notebooks in a box = 8.9 kg

=> Total weight = $$89\times8.9=792.1$$ kg

Let weight of new book = $$x$$ kg

=> New average = $$\frac{792.1+x}{90}=9$$

=> $$792.1+x=90\times9=810$$

=> $$x=810-792.1=17.9$$ kg

=> Ans - (C)

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