Given: The total question is 250
Marks for every correct answer is 2
Marks deduction for every wrong answer is 0.5
Total scored marks is 300
Calculations: Let the number of right answers be y
then, the number of wrong answers be (250 - y)
According to the question, we have
⇒ 2y - (250 - y)0.5 = 300
⇒ 2y - 125 + 0.5y = 300
⇒ 2.5y = 300 + 125
⇒ 2.5y = 425
⇒
y= ⇒ y = 170
Number of wrong answers is
⇒ 250 - y
⇒ 250 - 170
⇒ 80
∴ The number of wrong answers is 80.