Question

pls answer the ques step by step​

Answer 1

Answer:

126

step

let the correct answers be x

then the incorrect answer will be 180-x

we get 4 mark for each correct answer =4x

and -1 mark for each incorrect answer=-1*(180-x)=x-180

correct answers + incorrect answers=450

450=4x+x-180

5x=450+180

x=630/5=126

so number of correct answer is 126