Mrs. Chan, the P. E. teacher, is pairing off students to race against each other. Tracy can run 4 yards per second, and Alice can run 7 yards per second. Mrs. Chan decides to give Tracy a head start of 12 yards since she runs more slowly. Once the students start running, Alice will quickly catch up to Tracy. How far will Alice have to run? How long will that take?

21 yards in 3 seconds

Step-by-step explanation:

we give tracy the head start of 12 yards

then see how much she increases in 3 seconds at every second .

one second shes at 16 yards, 2 seconds she's at 20 yards & thats all the info we need

Alice runs 7 yards per second & we give her 3 seconds & how many yards she runs every second.

one second 7 yards , 2 seconds 14 yards & 3 seconds 21 yards & its at the 3 second that Alice has passed her.