Directions: Read the following information to answer the question.
Solution:
Red light flashes every 20 seconds
Green light flashes every 24 seconds
Therefore, they will flash together every 120 seconds
In every hour they will flash 3600/120= 30 times
Directions: Read the following information to answer the question.
Abhay, Ajay and Vijay wish to travel from town A to town B. They have one motorcycle which can be driven by any of them but can carry only two persons at a time. The distance between the two towns is 105 km and the speed at which they can walk is 5 kmph.
Directions: Read the following information to answer the question.
Let the usual speed of the man be x km/hr.
So, walking at the usual speed, in 1.25 hrs. he can cover 5/4 x km i.e, walking
at increased speed, he would cover (5x/4 + 1) km/hr. Now, usual time – new
time = 2, 96/x – 96/(5x/4 + 1) = 2
Solving the above equation we get, x = 12.
i.e. his usual speed = 12km/hr and his
increased speed = 16km/hr So, his usual
time = 8 hours and his new time = 6
hours
So, ratio of times = 8 : 6 = 4 : 3.
We can not have 1 at the unit’s place since it is the smallest number.
Number of ways ‘2’ at unit’s place..... hundred’s place can be filled in one way and remaining three places
in 1 × 2 × 3 = 6 ways.
Total number of ways in which 2 is at unit’s place is 6 × 1 = 6 ways.
Number of ways ‘3’ at unit’s place..... hundred’s place can be filled in two ways and remaining three places
in 1 × 2 × 3 = 6 ways.
Total number of ways in which 3 is at unit’s place is 6 × 2 = 12 ways.
Number of ways ‘4’ at unit’s place..... hundred’s place can be filled in three ways and remaining three
places in 1 × 2 × 3 = 6 ways.
Total number of ways in which 4 is at unit’s place is 6 × 3 = 18 ways.
Number of ways ‘5’ at unit’s place..... hundred’s place can be filled in four ways and remaining three places
in 1 × 2 × 3 = 6 ways.
Total number of ways in which 5 is at unit’s place is 6 × 4 = 24 ways.
So the total number of ways = 6 + 12 + 18 + 24 = 60.
