One pipe fills a cistern in 6 hours and another pipe fills it in 12 hours. How many hours does it take to fill the cistern when both pipes are open?
Answer and explanation
Correct answer: C.
- Step 1: Rates add: of the tank per hour. Step 2. Time hours. **Answer: . Why not the others:** averages the two times; adds the two times; subtracts the times.
Practise more Number, Algebra, Data Sufficiency and Probability.
Free questions with an explanation for every one, and full timed Högskoleprovet (Sweden) mock tests.
More Number, Algebra, Data Sufficiency and Probability questions
- A jacket costs 800 kr. During a sale its price is reduced by 25%. What is the sale price?
- Solve the equation .
- What is the next number in the sequence 3, 7, 11, 15, ... ?
- A train travels 240 km in 3 hours at a constant speed. How far does it travel in 5 hours at the same speed?
- What is the mean of the numbers 4, 8, 9 and 15?
- A rectangle has an area of 48 cm and a width of 6 cm. What is its perimeter?