Q.8 A cement company earns a profit of ? 8 per bag of white cement sold and a loss of Rs. 5 per bag of grey cement sold.
(a) The company sells 3,000 bags of white cement and 5,000 bags of grey cement in a month. What is its profit or loss?
(b) What is the number of white cement bags it must sell to have neither profit nor loss, if the number of grey bags sold is 6,400 bags.

(a) Profit on one white cement bag = Rs. 8
loss on one grey cement bag = Rs– 5
Profit on 3,000 bags of white cement
= Rs(8 × 3,000) = Rs 24,000
Loss on 5,000 bags of grey cement
= Rs (-5 × 5000) =Rs – 25,000
Total loss = – Rs25,000 + Rs24,000
= – Rs1000 i.e. Rs 1000
(b) Selling price of grey bags at a loss of ? 5
= Rs(5 × 6,400) – Rs 32,000
For no profit and no loss, the selling price of white bags = Rs32,000
Rate of selling price of white bags at a profit of Rs 8 per bag.
Therefore Number of white cement bags sold= 32,000÷8 = 4000 bags
Hence, the required number of bags = 4,000