In a class of 140 students, those who opted Science, Social Science, and languages were represented by 4 : 2 : 1 ratio. If a batch of 20 new students come to opt Science, then what will be the new ratio?

Correct option is A. 5:2:1
Let Number of students opted for Language be x
So, the number of students opted for Science and Social science is 4x and 2x respectively.
4x + 2x + x = 140
7x = 140
=> x = 20
After addition of 20 new students in Science
Number of students in science = 80 + 20 = 100
New ratio is 100:40:20 = 5:2:1