ja, yo is correct, just expand that formula with your calculator
each one is 5% bigger than pevious
each one=previous+previous*5%
each one=previous*1+previous*0.05
each one=previous*(1+0.05)
each one is 1.05 times of previous
so after n years, if today year size is P then

A=final size
so ya, after 18 years, n=18 so you get

A=2067.29 microliters
no u can only buy 6, or u dont have enough money for 7
No the 6 times 8 is 48 and the 9 times 12 is 108
So to find the area you should draw a line to make a right triangle then take the area of the 3 figures and add them together. See the picture.