Demo Exam
1) | A cistern has two taps (which fill it in 12 min. and 15 min. respectively) and an exhaust tap. When all the three taps are opened together it takes 20 min. to fill the cistern. How long will the exhaust tap take to empty it? |
1) | A cistern has two taps (which fill it in 12 min. and 15 min. respectively) and an exhaust tap. When all the three taps are opened together it takes 20 min. to fill the cistern. How long will the exhaust tap take to empty it? |