Question

plzzz answer this one

Answer 1

$Marks scored by Sujata=50 marks\\Mark for each correct answer=2 marks\\Mark for each incorrect answer=-1 mark\\If 3 marks was \\ awarded for a correct answer and -2 marks for incorrect,she would have scored 70 marks\\Let the number of questions in the test be 'x'\\A/Q\\2x=y+50...(i)\\3x=y+70....(ii)\\In (i)\\x=\frac{y+50}{2}\\In (ii) by substituting value of x we have,\\3\times (\frac{y+50}{2})=y+70\\=>3y+150=2y+140\\=>3y-2y=140-150\\y=-10\\In (i) by substituting value of y we have,\\2x=-10+50\\2x=40\\x=\frac{40}{2}\\x=20\\Therefore number of questions in the question paper =20$