Answer:
<h2>7.5$</h2>
Step-by-step explanation:

Well. im not 100% sure if this is correct. but what i did was did 5 x 8. which equals 40. so then i did 5 x 3. which equals 15. then i did 5 x 4. which equals 20. hopefully im correct. hope this helped! :)
6.76 x 10^11
this is because when you are placing something in a scientific notation you basically move the decimal place behind the last hole number in this case 6. and count the remaining numbers behind the decimal such as .76,000,000,000 which there 11 counting 76 with the zeros. then you place the number of places behind the decimal as an exponent of 11 and keep all real numbers besides 0 as your other half
Andrew has 10 pens bc it's half of twenty