17. An enterprise wants to understand the service quality of a certain department to its employees. It randomly surveyed 50 employees. Based on the evaluation scores of these 50 employees for the department, a frequency distribution histogram was drawn (as shown in the figure). The sample data are grouped into intervals [40, 50], [50, 60], [60, 70], [70, 80], [80, 90], [90, 100]. (1) Find the value of $a$ in the frequency distribution histogram; (2) Estimate the probability that an employee's evaluation score is not less than 80; (3) From the surveyed employees whose scores are in $[ 40,60 ]$, randomly select 2 people. Find the probability that both of their scores are in $[ 40,50 ]$. [Figure]
17. An enterprise wants to understand the service quality of a certain department to its employees. It randomly surveyed 50 employees. Based on the evaluation scores of these 50 employees for the department, a frequency distribution histogram was drawn (as shown in the figure). The sample data are grouped into intervals [40, 50], [50, 60], [60, 70], [70, 80], [80, 90], [90, 100].\\
(1) Find the value of $a$ in the frequency distribution histogram;\\
(2) Estimate the probability that an employee's evaluation score is not less than 80;\\
(3) From the surveyed employees whose scores are in $[ 40,60 ]$, randomly select 2 people. Find the probability that both of their scores are in $[ 40,50 ]$.\\
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