Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 30.
The average production of all cars in 2015 = (90 + 94 + 86 + 70)/4 = 85
The average production of all cars in 2019 = (120 + 130 + 110 + 100)/4 = 115
Difference = 115 - 85 = 30