Answer:
There were 30 8-points questions and 39 2-points question.
Process :-
Let the number of 8 points questions be x and 2 points questions be y.
Now,
8x+2y =318
x+y = 69
(according to the question)
x+y=69
x=69-y
plug in the value of x in the next equation 8x+2y=318,
8x+2y=318
or, 8(69-y)+2y=318
or, 552-8y+2y=318
or, -6y=318-552
or, -6y = -234
so, y = -234/-6
so, y = 39
Again,
x+y=69
or, x+y = 69
or, x+39 = 69
so, x = 30