Question

A single tree produces about 2.6 × 10^2 lb of oxygen each year. The Amazon rainforest has about 3.9 × 10^11 trees. About

Answer 1

$a\ single\ tree \ \ \ \rightarrow\ \ \ about\ 2.6 \cdot10^2\ lb\ of\ oxygen\ each\ year\\\\the\ rainforest\ \ \ \rightarrow\ \ \ about\ 3.9 \cdot 10^{11}\cdot2.6 \cdot10^2\ lb\ each\ year\\\\3.9 \cdot 10^{11}\cdot2.6 \cdot10^2=10.14\cdot10^{13}\\\\\\10.14\cdot10^{13}\ \ \ \rightarrow\ \ \ each\ year\\\\ \frac{\big{10.14\cdot10^{13}}}{\big{365}} \approx0.028\cdot10^{13}=2.8\cdot10^{11}\ \ \ \rightarrow\ \ \ dailly\\\\Ans.\ About\ 2.8\cdot 10^{11}\ lb\ each\ day.$

Answer 2

(2.6 * 10^2)/365 = 260/365
(260/365) * (3.9 * 10^11) = 2.778 * 10^12 (3.d.p.) or 2.8 * 10^12 (1.d.p.)