Solution: (1) According to the meaning of the question, the frequencies with scores within [70,80] are:

1-(0.0 10+0.0 15+0.0 15+0.025+0.005)× 10= 1-0.7=0.3,

∴ The ordinate in the histogram is frequency interval = 0.3 10 = 0.03, as shown in the figure;

(2) According to 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 [70,80] section is: 0.3× 60 =18;

∴ Take a sample with a capacity of 6 from the students with a score of [60,80] by stratified sampling.

Need to extract 2 people from [60, 70] score segment, respectively marked as M and N; Choose 4 people from [70,80] points, and mark them as A, B, C and D respectively;

Suppose two people are randomly selected from the sample, and the score segment [70,80] is the most 1 human event a,

Then all the basic events are: (m, n), (m, a), (m, b), (m, c), (m, d), (n, a), (n, b),

(n，c)，(n，d)，(a，b)，(a，c)，(a，d)，(b，c)，(c，d) * * 15，

The basic events contained in event A are: (m, n), (m, a), (m, b), (m, c), (m, d), (n, a),

(n, b), (n, c), (n, d)***9 kinds,

∴P(A)=9 15=35