Two students in the same Spanish class, Charlotte and Leroy, plan to get together after school to make vocabulary flashcards. Charlotte started on the project yesterday and has already made 10 flashcards. Leroy hasn't started yet. Since Charlotte makes 4 flashcards per minute and Leroy makes 6 flashcards per minute, Leroy will soon have the same number of flashcards. How long will that take? Open-ended: To determine how long it will take for Leroy to have the same number of flashcards as Charlotte, you need to calculate the difference in the number of flashcards they need to make and then divide by their combined rate. The specific time will depend on the number of flashcards Leroy needs to catch up.