In 40 years Imram will be 11 times as old as Sam right now
So if we call X the age of Imram, and S the age of Sam, we get to build the following equation:
X + 40 = 11 S
therefore S = (X + 40)/11
Second question:
It costs 10 d to support 4 L (legionaries) and 2 A (archers)
SO first equatin is (considering L what a legionary is paid per day, and A what an archer is paid per day):
10 = 4 L + 2 A
Second sentence:
It costs 5 d to support 2 legionaries and 2 archers. This translates to:
5 = 2 L + 2 A
Now solve for 2 A in both equations (substitution):
10 - 4 L = 2 A = 5 - 2 L
10 - 4 L = 5 - 2 L
10 - 5 = 4 L - 2 L
5 = 2 L
L = 2.5
So it costs 2.5 d to pay a legionary
Now solve for A in one of the equations:
2 A = 10 - 4 L
2 A = 10 - 10
2 A = 0
A = 0
So an archer gets paid 0 d (NOTHING!)