In a race of 200 metres, B can give a start of 10 metres to A and C can give a start of 20 metres to B. The start that C can give to A, in the same race, is

Direction: Study the following table carefully and answer the given questions. Table shows the of passed students in four schools and ratio between passed boys and girls among them. The ratio between failed boys and girls is reverse of passed ratio between them.

If the difference between the failed boys and girls is 25 in school S, then find the ratio between passed and failed students in School S?

The ratio between speed of boat in down stream and speed of stream is 9 : 1. If the speed of current is 3 km/hr, then find the distance travelled in upstream in 5 hours. 

42 cm a circular wire of diameter is folded into a rectangle whose sides are in the ratio 6: 5. What will be the area of the rectangle?

simplify the following equation
$$ (1-{1\over3})(1-{1\over4})(1-{1\over5})......(1-{1\over n})$$

The average of a,b,c is 20 and that of b,c,d is 25, if d=30, then the value of a is-

When the price of an audio system was reduced by 20%, the sale increased by 80%. What was the net effect on the sale?

There are some friends, all less than 20 years. When paired amongst themselves they realize that the sum of their ages is a multiple of 5. If their ages are distinct prime numbers, then the number of possible pairs are: