If you make a sketch, you see that the heading should be more towards the south and the angle between the straight line to the destination and the line showing the wind is 90-(10+20) = 60 degrees.

Now, use the sine rule...

\(\displaystyle \frac{sin(A)}{72} = \frac{sin(60)}{535}\)

You should get A = 6.69 degrees.

Therefore, the heading is 20 - 6.69 = 13.3 degrees, and in your notation, S13.3E.

Then, find the resultant speed. To do this, find the last angle of the triangle.

Angle = 180 - (60+6.69) = 113.7 degrees.

Then either by sine rule or cosine rule, find the last side of the triangle.

I'll use the cosine rule.

\(\displaystyle Speed = \sqrt{535^2 + 72^2 - 2(535)(72)cos(113.7)}\)

Speed = 567 km/hr.

Hence, time of travel = 625/567 = 1.10 hour or 1 hour 6 minutes