Question

A petrol tank at a filling station has a capacity of 400 litres. The attendant sells 40 litres of petrol from the tank to one customer and then replenishes it with kerosene oil. This process is repeated with six customers. What quantity of pure petrol will the seventh customer get when he purchases 40 litres of petrol?

Answer 1

Answer:

21.25764 Litre or 21.26 Litre

Step-by-step explanation:

A petrol tank at a filling station has a capacity of 400 litres. The attendant sells 40 litres of petrol from the tank to one customer and then replenishes it with kerosene oil. This process is repeated with six customers. What quantity of pure petrol will the seventh customer get when he purchases 40 litres of petrol?

First Customer Get Pure 40 L Petrol

Then tank has 400-40 =360 L Petrol & 40 Litre Kerosene oil

Second customer get = (360/400)*40 = 36 Litre Petrol & 4 Litre kerosene oil

Then tank has = 360-36 = 324 Litre Petrol  & 40-4+40 = 76 Litre Kerosene oil

Third Customer Gets = (324/400)*40 = 32.4 Lite Petrol  & 7.6 Litre kerosene

Now Tank has 324-32.4 = 291.6 Litre petrol

At every Transaction Petrol is reduced by 10 %

After 6 customers petrol left

= 400 ( 1 - 10/100)⁶

= 400 (0.9)⁶

= 212.5764 Litre   & kerosene = 187.4236 Litre

7th Customer Gets Pure petrol =  (212.5764/400)*40 = 21.25764 Litre

pure petrol the seventh customer get when he purchases 40 litres of petrol = 21.25764 litre

= 21.26 Litre