A and B can do a work in 20days, B and C in 25days, C and A in 30days. If A,B and C work together , they will complete the work in?  Choose the correct answer
A) 10days
B) 12days
C) 16days
D) 20days
E) 25days
A+B 1day work = 1/20   B+16days 1day work +  1= 
<gadget id="calculator">+  1</gadget>
<output>1</output>
1/20   B+16days 1day work= 1/25   16days+A 1day work = 1/30   Adding we get 2(A+B+16days)  +  1= 
<gadget id="calculator"> +  1</gadget>
<output>1</output>
1/30   Adding we get 2(A+B+16days)= 1/20 + 1/25 + 1/30 = 37/300   A+B+16days 1 day work = 37/600   A,B,16days can finish the work in 600/37 days = 16days approximately   Answer is 16days
<result>C</result>
A and B can do a work in 20days, B and C in 25days, C and A in 30days. If A,B and C work together , they will complete the work in?