Please tell me the answer of this question - 4

Dear Student,
Assuming you require the answer for the 4th subquestion(i.e d):-
$$\begin{gathered} Let the 2 numbers be x and y \\ According to 1st condition, \\ x+y=60 \\ According to 2nd condition, \\ x-y=30 (We consider x>y) \\ Adding both the equations, we get, \\ 2x=90, i.e x=45 \\ Resubstituting value of x in 1st equation, we get, \\ y=60-x=60-45=15 \\ Hence the 2 numbers are 45 and 15 and this is the solution of the equation \end{gathered}$$
Regards.