Let X be number of bushwalker and Y be number of outback.

Then X = Y + 20% of Y => X = Y + Y/5 (since 20% is the same as 1/5) => X = 6Y/5.

X = 6Y/5 .... (1)

Profit: 350 X + 200 Y = 177 000 => 35X + 20Y = 17700 => 7X + 4Y = 3540

7X + 4Y = 3540 .... (2)

Solve equations (1) and (2) simultaneously (I suggest using the substitution method).