He will need 135 more points to allow him to have an A in the class
Let, Number of multiple choice = x
Number of short answer question = y
Now, x + y = 20
& 3x + 11y = 100
Multiply 1st equation by 3, and subtract from eq,2,
3x + 3y = 60
After subtraction,
8y = 40
y = 40/8
y = 5
Now, substitute in eq (1),
x + 5 = 20
x = 15
In short, There are 15 Multiple choice & 5 short answer questions
Hope this helps!
Step-by-step explanation:
Given,
s=5
t=8
solution,
= 3st² - s²
= 3*5*8² - 5²
= 3*5*64 - 25
= 960 - 25
= 935