Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is: Choose one
A) 14	B) 12	C) 15	D) 16	E) 20
Filled in 2 hrs = 2/6 = 1/3   remain = (1-1/3)=2/3   (14+B)'S 7 HRS WORK = 2/3   (14+B)'S 1 hr work = 2/21   C'S 1 hr work = (14+B+C)'S 1 hr work - (14+B)'S 1 hr work   =(1/6-2/21)=1/14   =&gt;c alone fill tank in 14 hrs   14NSWER 14
<result>A</result>
Three pipes A, B and C can fill a tank in 6 hours. After working at it together for 2 hours, C is closed and A and B can fill the remaining part in 7 hours. The number of hours taken by C alone to fill the tank is: