1. The case the mode of all salaries is less than 60k, I'll take an example to prove it:
No. of employees: 5
Avarage salary :60k, total 300k
Mode 20k (2 people), 1 with 90k, 1 with 100k, 1 with 70k, only 2 have salaries below 60k -> No
Mode 20k (4 people), 1 with 220k, now 4 have salaries below 60k -> Yes
So 1 is not suff

2. 62.5k is median, so the no. of employees who have salaries below 62.5k is the same to the no. of employees who have salaries above 62.5k . Therefore, the no. of employees who have salary below 62.5k is equal of less than half the total no. of employees. The maximum no. of employees who have salaries below 60k is less than the no. of employees who have salary below 62.5k 1 unit. (As John has 62k, and 62>60). So the maximum no. of employees who have salaries below 60k is less than
half the total no. of employees. Thus, the answer is No.
2 is suff.