Multiple Choice Questions10% discount and then 20% discount in succession is equivalent to total discount of
15%
24%
30%
28%
18 yr ago, the ratio of A's age to B's age was 8 : 13. Their present ratios are 5 : 7. What is the present age of A?
70 yr
60 yr
40 yr
50 yr
In certain years a sum of money is doubled itself at 
simple interest per annum, then the required time will be
16 yr
8 yr
Walking at the rate of 4 km/h a man covers certain distance in 2 h 45 min. Running at a speed of 16.5 km/h the man will cover the same distance in how many minutes?
45
50
40
35
729 mL of a mixture contains milk and water in the ratio 7 : 2. How much more water is to be added to get a new mixture containing milk and water in the ratio 7 : 3?
52 mL
60 mL
71 mL
81 mL
D.
81 mL
Quantity of mixture = 729 mL, Milk : Water = 7 : 2
Quantity of milk:
∴ Water = 729 - 567 = 162 mL
Let x water be added for new mixture:
∴ Quantity of water to be added = 81 mL
A tap can empty a tank in 30 min. A second tap can empty it in 45 min. If both the taps operate simultaneously, how much time is needed to empty the tank?
30 min
14 min
15 min
18 min
The population of a town increases by 5% every year. If the present population is 9261, the population 3 yr ago was
8000
7500
5700
6000
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