Table – Weekly Fuel Usage (lines)

Vehicle	Mon	Tue	Wed	Thu	Fri
Truck1	18	20	22	21	19
Truck 2	25	24	26	23	24

What is the overall average daily fuel usage for both trucks?

Correct option is B

Given :

Weekly fuel usage (in litres)

Truck 1: 18, 20, 22, 21, 19

Truck 2: 25, 24, 26, 23, 24

Number of days = 5

Solution :

Total fuel used by Truck 1:
18 + 20 + 22 + 21 + 19 = 100

Total fuel used by Truck 2:
25 + 24 + 26 + 23 + 24 = 122

Total fuel used by both trucks:
100 + 122 = 222
The number of data points is the number of trucks multiplied by the number of days reported.

There are 2 trucks and 5 days, so there are $$2\times 5=$$​10 data points. 

Overall average daily fuel usage:
​$$\frac{222}{10} = 22.$$​2