9) 35% of the 12,000 are 50-64 years old.
12,000 x 0.35 = 4,200
4,200 people were 50-64 years old
10) 25% of 596 people are over 64 years old
596 x 0.25 = 194
194 people were older than 64
11) yes, he is correct because 450 x 10%=45 and 450 x 30%=135
