Answer
a) 3
b) Unlimited
c) 3
d) 2
e) 5
f) Ambiguous
Work Step by Step
a) all numbers that aren't 0's are significant
b) this is a defined quantity due to the pennies, thus, making it unlimited
c) the 1 and 1 are significant, and the 1 zero is an interior zero that is a sig fig
d) 9 and 9 are sig figs, the zeroes aren't included because they are leading
e) 1, 4, 5 are significant and the zeroes are trailing zeroes marked with a decimal making them sig figs
f) you would assume 2 sig figs because of the 2 and 1 but it is ambiguous because the trailing zeroes imply the use of a decimal point, thus, making it ambiguous