Which line shows the first error in the solution?

Tatiana reads 40 pages of her book every night for x number of nights. write an expression that shows the number of pages she has read

Aresearch study is done to find the average age of all u. s. factory workers. the researchers asked every factory worker in ohio what their birth year is. this research is an example of a census survey convenience sample simple random sample

Asap! i need this done today and i really don’t understand it. some one ! will mark