Question

Two pipes p and qcan fill a tank in 10 hours and 12 hours respectively and r can empty the tank in 6 hours.If pipes p,q,r are opened at 7 am,8 am, and 11 am respectively. then when the tank will be full of water?​

Answer 1

Answer:

⇒Pipe A opens at 8 am. it fins 4 units/hr

⇒ Pipe A fills 4×3=12unit in 3 hrs So by 11 am. it fills 12 units

Similarly

⇒ Pipe B opens at 9 am. it fills 5 units/hr

⇒ By 11 am it fills 5×2=10 units total water in tank till 11 am =12+10=22 units

⇒ Now, 11 am onwards all pipes work simultaneously including emptying pipe.

⇒ (A+B+C) efficiency is 4+5−15=−6 units

⇒ now 6 unit will be emptied per hour then Tank will be emp tied at after

⇒ the tank will be emptied at

⇒  11am+3hrs40min.

⇒ 2 : 40pm