MATLAB Programming Techniques Course quiz problem

I really can't understand why I can't get this question right. The same question was closed without a proper answer: https://it.mathworks.com/matlabcentral/answers/1591624-mathlab-programing-techniques-online-course-problem

The first option occupies 8e9 < 1.015e10 bytes

The second 8e4 < 1.015e10 bytes

The third 8e5 < 1.015e10 bytes

The fourth 8e9 < 1.015e10 bytes

The fifth should be 1.6e10 > 1.015e10 bytes, so it should be the only right answer

Still, it's listed as wrong and I can't wrap my head around this. It's the only thing in the whole course I can't do and I really need the certification ASAP

[Shinto Thomas]

could please show the exact answer , as of my knowledge we have to select all option for the correct answer . But this is wrong according to the system.

[Sharmila]

the ans is option 3 & 5

[Shinto Thomas]

Thank you Sharmila. the last code uses 2*8*10e9=16e9=1.6e10 bytes and

this less than 1.7e10. Then how we choose the last option as a right answer.

[bhargav ram akkaraju]

Tq sharmilaa.

[SENA REDDY]

Option 3 and 5

Answer 1

[Dave B]

You've marked the second and third lines as being 8e4 and 8e5 bytes, but this is incorrect.

Hint: how many elements are in a martix creted by ones/zeros with one argument?

x=rand(7);
size(x)

ans = 1×2

7 7

[Luca Scagnellato]

Thanks Dave for the quick reply. I feel so dumb right now :)

After all these years using MATLAB I still forget these details, hopefully after this I won't anymore