Study the given table and answer the question that follows.
The given table shows the production of different types of refrigerators in a company.
Type of refridgerator sold over the years
Year Type A Type B TypeC
2011 2018 1800 1932
2012 2040 1890 1800
2013 2035 1910 1890
2014 2020 1940 1978
2015 1997 1960 1900
In which of the given year(s) was the production of B type refrigerator closest to its average production over the given years?
The measures of the three angles of a triangle are in the ratio 17 : 13 : 15. Find the positive difference between the greatest and the smallest of these three angles.
A certain sum of money becomes seven times itself when invested at a certain rate of simple interest, in 14 years. How much time (in years, rounded off to 2 decimal places) will it take to become 18 times itself at the same rate?