Solving this rate of decay problem -- Mass loss calculation

[chwala]

Homework Statement:

Kindly see attached.

Relevant Equations:

exponential function and its derivatives

My interest is on question $11.ii$ only. I think there is a mistake on the markscheme...i just need a second opinion on this...find attached the question and markscheme...

markscheme here:

it ought to be,
$e^{0.0277t}=1.6797$

 

[Orodruin]

Given the precision in the previous step, quoting anything more precise 1.7 is probably pushing it.

 

[chwala]

Given the precision in the previous step, quoting anything more precise 1.7 is probably pushing it.

I think mark scheme is just fine...you are also correct...i would probably say $1.68$ to 3 significant figures...