In a trapezium ABCD, AB and DC are parallel sides and ∠ ADC = 90°. If AB = 15 cm, CD = 40 cm and diagonal AC = 41 cm. Then the area of the trapezium ABCD is
A wholesaler sells a watch to a retailer at a gain of 35% and the retailer sells it to a customer at a loss of 25%. If the customer pays Rs 2379.375, what had it cost the wholesaler?