So on the first day * * * caught a cold X+ 1 person.
The next day * * * caught a cold (X+ 1)X people.
Two days * * * cold X+ 1+(X+ 1)X=36.
X=5
(2) On the third day, 36+36×3= 144 people caught a cold.
The fourth day144+144×1= 288 people.
No, you can ask.