Xue Jing's answer to Ray's Secondary 4 E Maths Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Xue Jing
Xue Jing's answer
25 answers (A Helpful Person)
1st
Create a equation with only one unknown. Understand that 120 is 1/3 of 360