please explain!

Question 6 1 pts TABLE 2-5 The following are the duration in minutes of a sample of long-distance phone calls made within the continental United States reported by one long-distance carrier Time in Minutes) O but less than 5 5 but less than 10 10 but less than 15 15 but less than 20 20 but less than 25 25 but less than 30 30 or more Relative Frequency 0.37 0.22 0.15 0.10 0.07 0.07 0.02 Referring to Table 2-5, if 10 calls lasted 30 minutes or more, how many calls lasted less than 5 minutes? 500 10 185 295