Each pair of interior angle and the exterior angle
So the exterior angle = 360° - the interior angle.
Step-by-step explanation:
On Monday maggie ran n miles.
On Tuesday, she she ran 90% of the number of miles that she ran on Monday i.e
.
On Wednesday, she ran 50% of the number of miles that she ran on Tuesday i.e. 
First expression : n+0.9n = 1.9 n
Second expression : n + 0.9 n + 0.45 n = 2.35 n
Hence, this is the required solution.
The second one should be the answer