Answer:
2
Step-by-step explanation:
You can calculate them out and check which one is the most accurate
so if one of the choices was 1/3 of 50, then you would do:
1/3 in the calculator (should be 0.333...) times 50
And you can compare it with the EXACT number, which is:
0.25*53=13.25
This way you can test all the options
X - Ollie's age
8 is subtracted from Ollie's age = x-8
the result is the same as
subtracting 16 from 3 times his age = 3x-16

Ollie is 4 years old.