Study the given table and answer the question that follows.

The table gives the number of graduate students enrolled in 4 different colleges A, B, C, and D in a city over the years 2010 to 2014 and also the number of students who passed in the final examination during these years.

Year	2010	2010	2011	2011	2012	2012	2013	2013	2014	2014
College	Enrolled	Pass	Enrolled	Pass	Enrolled	Pass	Enrolled	Pass	Enrolled	Pass
A	680	620	600	560	720	700	800	760	750	700
B	550	530	450	420	600	550	650	620	700	680
C	480	450	520	500	580	550	620	600	720	700
D	710	650	750	710	680	640	720	690	740	710

Find the percentage of students who passed from college B for all the years put together to the number of students from college B during all the years. (rounded to 2 decimals)

If (a + b + c) = 13, and (ab + bc + ca) = 54, find the value of (a² + b² + c²).

If $\rm \frac{21\ cosA+3\ sinA}{3\ cosA+4\ sinA}$ = 2, then find the value of cot A

A can complete a piece of work alone in 120 days, while A and B, working together, can complete this piece of work in 72 days. In how many days can B, working alone, complete this piece of work?