Solve similar triangles advanced solve for x

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?

Abag contains pieces of paper numbered from 5 to 9. a piece of paper is drawn at random. what is the theoretical probability of drawing a number less than 8?

Aculinary club earns $1360 from a dinner service. they sold 45 adult meals and 80 student meals. an adult meal costs twice as much as a student meal. what is the cost of an adult meal?