Anser is B). Subtract smallest number
1.68 mm per year for 1.5 years could be rewritten as
(2.00-0.32) mm per year for 1.5 yrs.
Multiply: (1.5 yrs)(2.00-0.32)(mm/yr) = 3 mm + 0.48 mm = 3.48 mm
This approach makes use of the distributive property of multiplication.
alligators:
x = total number of alligators
n = number of years
x=20x1.25^n
crocodiles:
y = total number of crocodiles
n = number of years
y=25+10n