Ques:- The average age of 12 students is 20 years. If the age of one more student is included, the average decreases by 1. What is the age of the new student?
A. 5 years
B. 6 years
C. 7 years
D. 9 years
Ques:- If a 200 m long train crosses a platform of the same length as that of the train in 20 seconds, then the speed of the train is
A. 50 km/hr
B. 60 km/hr
C. 70 km/hr
D. 72 km/hr