4/5 (four fifth) of 500 pages is [tex] \frac{4}{5} [/tex] times 500
[tex] \frac{4}{5} [/tex] times 500 is [tex] \frac{4}{5}*500
[/tex],
which is [tex]4* \frac{500}{5}=4*100=400 [/tex]
So Dayo read 400 pages of 500.
Dayo has not yet read 500-400=100 pages.
Answer: 100
