A student needs to read a 300-page book in 5 days. If the student reads 20 pages more each day than the previous day, how many pages does the student read on the first day?

Jawaban: 44

Let x be first day pages. Sum of arithmetic series: 5/2[2x+4×20]=300 → 5(2x+80)/2=300 → 5(2x+80)=600 → 2x+80=120 → 2x=40 → x=20. Wait, that gives 20, not in options. Recalc: 5/2[2x+4*20]=300 ⇒ 5(2x+80)=600 ⇒ 10x+400=600 ⇒ 10x=200 ⇒ x=20. Not in options. So flawed. Discard.