How to write a word problem

What type of word problem like these:

if Michael is 3 times older than his brother Donald who is 12 then how old is Michael?

the students of Oakwood academy are having a fundraiser for the school talent show. they have $138 but the cost of equipment is $1,388 ho cover the how much more do they need to cover equipment costs?

or it cost twelve dollars to get into the fair. tickets for rides cost extra and are d dollars each. if Tyra buys 20 tickets, how much would it cost her for the fair?