Answer:Amount watched at night by Ingrid = 1/6
Explanation:
Let total amount of movie to watch = 1 whole since we are dealing with fractions
Amount of movie watched in the morning = 1/2
Amount watched at night = x
Amount remaining at the end of day = 1/3
So that to find amount watched at night we use
Total amount of movie to watch - Amount watched in morning and night = Amount remaining to watch
1 - ( 1/2+ x ) = 1/3
1- 1/3 = 1/2 + x
2/3 =1/2+ x
2/3 - 1/2 = x
4-3/6 = x
1/6=X
x= Amount watched at night = 1/6