I don't understand these two problem. Can any NN help me? Thanks!

Prep 1-3
For every positive even integar n, the function h(n) is defined to be the product of all the even integars from 2 to n, inclusive, if p is the smallest prime factoe of h(100)+1, then p is
A. between 2 and 10
B. between 10 and 20
C. between 20 and 30
D. between 30 and 40
E. greater than 40
Answer: E

Prep 1-13.
Before being simplified, the instruction for computing income tax in Country R were to add 2 percent of one's annual income to the average(arithmetic mean) of 100 units of Country R's currency and 1 percent of one's annual income. Which of the following represents the simplified formula for computing the income tax, in Country R's currency, for a person in that country whose annual income is I?
A.50+I/200
B.50+3I/100
C.50+I/40
D.100+I/50
E.100+3I/100
Answer: C