Answer
a) no
b) yes
c) yes
d) yes
e) no
f) no
Work Step by Step
A number is composite if and only if it can be listed as a product of factors, in addition to the trivial factorization of $n=n\cdot 1$. The numbers in this section can be factored according to the chart found earlier in the section.
a) 21=3*7, so composite
b) 29 is prime
c) 71 is prime
d) 97 is prime
e) 111=3*37
f) 143=11*13