15a)
[tex] \frac{15}{100} \times 450 = \frac{15 \times 450}{100} = \frac{6750}{100} = 67.5\%[/tex]
b)
[tex] \frac{220}{100} \times 60= \frac{60 \times 220}{100} = \frac{13200}{100} = 132[/tex]
c)
[tex] \frac{14}{100} \times 420 = \frac{14 \times 420}{100} = \frac{5885}{100} = 58.8\% [/tex]