Students of class 8 took a test and got the following marks 75,70,18,32,82,66,83,77,74,41,47,89,45,39,71,85,32,29,49,43,75,77,45,74,15,77,72 If we put the marks in various ranges like 10-19, 20-29, 30-39 and so on, in which range would the most number of students have gotten marks?
Shen is participating in a race. The probability that he will come first in the race is 0.3. The probability that he will come second in the race is 0.25. The probability that he will come in 3rd is 0.35, and the probability that he will be 4th is 0.1. What is the probability that he will win 2nd position or better in the race?
Li Mei covers a certain distance in a certain time. If 1/4 of the distance is covered in 3/4 of the time with speed V1 and the rest of the 3/4 distance in 1/4 of the time with speed V2, then find the ratio V1:V2.