A motorcycle is twice as fast as a car and car is thrice as fast as scooter. The journey covered by scooter in 54 minutes will be covered by a motorcycle in?
(a)8 minutes
(b)12 minutes
(c)9 minutes
(d)none of these
Radhika,sanya and devika can do a piece of work in 36,48 and 72 days respectively. They work alternativey,First day-Radhika,second day-Sanya,Third day-Devika,Fourth day-Radhika and so on.How many days will be needed to complete the work like this way?
In a class there are 80 students and their average marks in the annual examination is 45.If the average marks of passed students is 55 and the average marks of failed students is 30,then find out the number of students who failed.
The average age of five members of a family is 22 years.if youngest member is 5 year old,what was the average age of family at the time of the birth of youngest member?
(a)21 years
(b)22 1/2 years
(c)21 1/4 years
(d)none of these
A tank is 7 m long and 4 m wide.At what speed should water run through a pipe 5 cm broad and 4 cm deep so that in 6hr and 18 minutes water level in the tank risese by 4.5 m?
In a class,the number of boys and girls are in the ratio 4:5. If 10 more boys join the class,the ratio of numbers of boys and girls become 6:5. How many girls are there in the class?