The frequency of (1) score in [70,80] is:1-(0.010+0.015+0.025+0.005).

(2) Judging from the meaning of the question, the number of people in the [60,70] score segment is 0. 15×60=9,

The number of people in the [70,80] section is: 0.3×60= 18,

Then, 2 people and 4 people were selected in the [60, 70] and [70, 80] score segments respectively.