Correct Answer - Option 1 : Rs. 20.87
Given:
Deepak spends Rs 6000 on petrol for four consecutive years at the rate of Rs 10, Rs 20, Rs 40 and Rs 60 per litre.
Formula:
If A is the average of n terms,
then A = (Sum of all “n” terms)/(total number of terms).
Calculation:
According to the question,
In 1st year Deepak spends Rs 6000 on petrol at the rate of Rs 10.
The total quantity of petrol purchased by Deepak in 1st year = 6000/10 = 600 litres.
In the 2nd year, Deepak spends Rs 6000 on petrol at the rate of Rs 20.
The total quantity of petrol purchased by Deepak in 2nd year = 6000/20 = 300 litres.
In the 3rd year, Deepak spends Rs 6000 on petrol at the rate of Rs 40
The total quantity of petrol purchased by Deepak in 3rd year = 6000/40 = 150 litres.
In the 4th year, Deepak spends Rs 6000 on petrol at the rate of Rs 60
The total quantity of petrol purchased by Deepak in the 4th year = 6000/60 = 100 litres.
The total quantity of petrol purchased by Deepak in four consecutive years
⇒ (600 + 300 + 150 + 100) litres = 1150 litres.
Total money spent by Deepak on petrol in four consecutive years
⇒ (Rs 6000) × 4 = Rs 24000.
Average cost of petrol = (Rs 24000)/1150
⇒ Rs 20.87.
∴ The average cost of petrol per litre is Rs 20.87.
