Answer:
Part A : 9.555 . 10^38
Part B : 7.4 . 10^-3
Step-by-step explanation:
<h3>Part A</h3>

<h3>Part B</h3>


A blood cell is too small. So the more reasonable measurement is 0.0074mm.
Try this option:
the final price of the first machine after discount is:
(1-0.3)*495=346.5$;
the final price of the second machine after all the discount is:
(1-(0.2+0.2*0.1))*495=386.1$.
Short explanation: the additional 10% off is 2% of the initial price for the second machine; the final discount of the second machine is 22%.