Solving a system of equations

Question

Kate and Riley are reading the same book. Kate reads 1/3 page per minute, and Riley reads 3/4 page per minute. Kate has read 70 pages, while Riley has read 30 pages. If they both resume reading together, eventually Riley will catch up to Kate. On what page will that occur?

Answer 1

kate 70+m/4

Riley 30+3m/4

set them equal

70+m/4 = 30+3m/4

40 = 2m/4 = m/2

m =80 minutes and Riley catches up to kate

at page 70+80/4 = page 90