(i) Total number of engineers = 40
Number of engineers living less than 7 km from their place of work = 9
Hence, required probability that an engineer lives less than 7 km from her place of work, P = 9/40
(ii) Number of engineers living more than or equal to 7 km from their place of work = 40 − 9 = 31
Hence, required probability that an engineer lives more than or equal to 7 km from her place of work, P = 31/40
(iii) Number of engineers living within 1/2 km from her place of work = 0
Hence, required probability that an engineer lives within 1/2 km from her place of work, P = 0