In a particular cathode ray tube, the measured beam current is 27.0 µA. How many Coulombs of charge strike the tube screen every 45.0s?

I thought it was current*time/coulombs and ive also done current*time/charge of an electron and a few other variations but they are all wrong. any guidance?

and another question: A resistor is constructed of a carbon rod that has a uniform cross-sectional area of 6.10 mm2. When a potential difference of 24.4 V is applied across the ends of the rod, there is a current of 8.50 mA in the rod.

a) Find the resistance of the rod in kΩ.
Find the rod`s length in meters. The resistivity of carbon is 3.5x10-5 Ωm

i solved a in ohms and then converted to kilohms and got it right, so for part B i used the formula R=pL/A and manipulated it to be L = RA/p. I converted the mm2 to m2 and im not getting this part right at all? i used an online converter for the mm2 to double check and it gave me 6.1mm² = 0.0000061000m²

assuming constant current
charge= current*time
27*10^-6 amp * 45 seconds

compare that to 1 colubmb = 1amp*1 second

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6.1mm² = 0.0000061000m²
is correct
idk what else you could be messing up on, formula is correct

i must have just been calculating it wrong. Thank you i got it right