The problem is missing some parts but nevertheless here is the solution:
Given:
Mean is 28
Standard deviation is 5
So we denote the problem as x <= 2
For X ~ N (28, 5^2)
we are looking for the percentage:
P{X>24} = P {Z>z}
Where z = (24-28)/5 = 4/5 = - 0.80.
P {Z> -0.80} = 1 - P{Z< -0.80} = 1 - 0.2119.
Or in percentage, it is replaced as P{Z< -0.80} = 0.2119, 21.19%.
