D) increase the thrust force and increase the mass of the rocket.
Figure this out as though no digits are present. You can choose 8 of the 26 letters and that's it.
26^8 [you can allow repeating letters] = 2.088 * 10^11
The total number of ways that can be chosen with letters and digits intermixed = 36^8
The probability of getting no numbers is 26^8 / 36^8 or (26/36)^8 = 0.07402
So the probability that there were be at least one digit is
1 - 0.07402 = 0.92598
The medical students m>12,the temperature of students s=>25, and the ideal candidate c=<5
100 divided by 2 equals to 50