Question

Rohan gets 5 marks for each correct question and losses 3 marks for each wrong question. He answered 36 questions in all and obtained a total of 52 marks ,then find the number of questions solved correctly by Rohan

Answer 1

let the right answer be 'x' and wrong be 'y'
according to question,
x+y=36.........(1)
5x-3y=52........(2)

from equation (1) we have,
x=36-y........(3)
put the value of equation (3) in equation (2)
5x-3y=52
5(36-y)-3y=52
180-5y-3y=52
-8y=52-180
-8y=-128
y=-128/-8
y=128/8
y=16
put the value of y in equation (3)
x=36-y
x=36-16
x=20
20questions were solved correctly by rohan