It takes 30 minutes to empty a half-full tank by draining it at a constant rate. It is decided to simultaneously pump water into the half-full tank while draining it. What is the rate at which water has to be pumped in so that it gets fully filled in 10 minutes?
4 times the draining rate
Let capacity be V. The draining rate is V/60 per minute. Filling the remaining V/2 in 10 minutes requires net inflow V/20. Thus pump rate = V/20+V/60=V/15, four times the draining rate.
The table shows the monthly expenditure of Saumya. What percent of her monthly salary is she able to save?
| Expense | Amount |
| Food | 5,000 |
| Rent | 20,000 |
| Travel | 10,000 |
| Clothing | 3,000 |
| Miscellaneous | 15,000 |
| Savings | 7,500 |
Following table provides figures (in rupees) on annual expenditure of a firm for two years – 2010 and 2011.
Category | 2010 | 2011 |
Raw material | 5200 | 6240 |
Power & fuel | 7000 | 9450 |
Salary & wages | 9000 | 12600 |
Plant & machinery | 20000 | 25000 |
Advertising | 15000 | 19500 |
Research & Development | 22000 | 26400 |
In 2011, which of the following two categories have registered increase by same percentage?
The time spent to study history and chemistry is 4 hours 30 minutes. Then the student studied physics for
If the student studied chemistry for 3 hours, then he/she studied geography for
If the student studied 10 hours in a day, then he/she studied mathematics for