I think it’s d because it’s like similar
Let there be 2x science and 5x art books
<span>science books sold = 2x × 0.2 = 0.4x </span>
<span>science books unsold = 2x – 0.4x = 1.6x </span>
<span>art books sold = 5x × 0.2 = x </span>
<span>art books unsold = 5x – x = 4x </span>
<span>total books unsold = 1.6x + 4x = 5.6x </span>
<span>5.6x = 2240 </span>
<span>x = 400 </span>
<span>2x science = 800 </span>
<span>and 5x art books = 2000 </span>
750+20(30)=1350
Or do you need to explain it?
Answer:

Step-by-step explanation:
percentage of graduates with loan = 62%
total sample = 50
Number of student in the sample with student loan
= (percentage of graduates with loan) x (total sample)
= 62% x 50
= 31
Proportion of student in the sample with student loan = 
3/6x+9=8
3x+9=8
3x=-1
x= -1/3