Question

A recycling machine recycles $5.8\times {10}^{10}$ pounds of waste on Day 1 and $9.5\times {10}^{12}$ pounds on Day 2. What is the total amount of waste recycled by the machine in two days ?

• A. $955.8\times {10}^{12}$ lb
• B. $9.558\times {10}^{10}$ lb
• C. $95.58\times {10}^8$ lb
• D. $9.558\times {10}^{12}$ lb

Answer 1

The correct option is D $9.558\times {10}^{12}$ lb

Amount of waste recycled on Day 1 $=5.8\times {10}^{10}$lb
Amount of waste recycled on Day 2 $=9.5\times {10}^{12}$lb

Amount of waste recycled in two days
= amount of waste recycled on Day 1 + amount of waste recycled on Day 2
$=5.8\times {10}^{10}+9.5\times {10}^{12}$

Make the exponents of both values the same
$=5.8\times {10}^{10}+9.5\times {10}^{12}$
$=5.8\times {10}^{10}+950\times {10}^{10}$
$=(5.8+950)\times {10}^{10}$
$=955.8\times {10}^{10}$
$=9.558\times {10}^{12}$

Therefore, the total amount of waste recycled in 2 days is $9.558\times {10}^{12}$ lb.