The table below gives details of coal production in four different states for the years 2014 to 2018. Observe the table and answer the question below.

State	2014	2015	2016	2017	2018
A	84	86	85	82	85
B	168	164	162	163	145
C	178	180	181	182	185
D	86	79	84	76	74

Coal production (in thousands)
For which State has the percentage contribution to the overall coal production NOT dropped even once during the 5-year period? (Percentage calculation rounded off to the nearest integer).

Correct option is B

Solution:  

​$$\text{State A:} \\\text{2014: } \left( \frac{84}{516} \right) \times 100 \approx 16\% \\\text{2015: } \left( \frac{86}{509} \right) \times 100 \approx 17\% \\\text{2016: } \left( \frac{85}{512} \right) \times 100 \approx 17\% \\\text{2017: } \left( \frac{82}{503} \right) \times 100 \approx 16\% \\\text{2018: } \left( \frac{85}{489} \right) \times 100 \approx 17\%$$ 

State A's percentage  drops in 2017

​$$\text{State B:} \\\text{2014: } \left( \frac{168}{516} \right) \times 100 \approx 33\% \\\text{2015: } \left( \frac{164}{509} \right) \times 100 \approx 32\% \\\text{2016: } \left( \frac{162}{512} \right) \times 100 \approx 32\% \\\text{2017: } \left( \frac{163}{503} \right) \times 100 \approx 32\% \\\text{2018: } \left( \frac{145}{489} \right) \times 100 \approx 30\%$$ 

State B's percentage drops from 33% to 30%. 

​$$\text{State C:} \\\text{2014: } \left( \frac{178}{516} \right) \times 100 \approx 34\% \\\text{2015: } \left( \frac{180}{509} \right) \times 100 \approx 35\% \\\text{2016: } \left( \frac{181}{512} \right) \times 100 \approx 35\% \\\text{2017: } \left( \frac{182}{503} \right) \times 100 \approx 36\% \\\text{2018: } \left( \frac{185}{489} \right) \times 100 \approx 38\%$$ 

State C's percentage continuously increases. 

​$$\text{State D:} \\\text{2014: } \left( \frac{86}{516} \right) \times 100 \approx 17\% \\\text{2015: } \left( \frac{79}{509} \right) \times 100 \approx 16\% \\\text{2016: } \left( \frac{84}{512} \right) \times 100 \approx 16\% \\\text{2017: } \left( \frac{76}{503} \right) \times 100 \approx 15\% \\\text{2018: } \left( \frac{74}{489} \right) \times 100 \approx 15\%$$ 

State D's percentage drops every year. 

Thus for which State C  the percentage contribution to the overall coal production NOT dropped even once during the 5-year period .