Answer:
6 lockers have both students' stickers
Step-by-step explanation:
There are 130 lockers in the hallway
Janine goes down a hallway in the school and puts a sticker on every fourth locker.
Janine= 4th, 8th, 12th, 16th, 20th, 24th, 28th, 32nd, 36th, 40th, 44th, 48th, 52nd, 56th, 60th, 64th, 68th, 72nd, 76th, 80th, 84th, 88th, 92nd, 96th, 100th, 104th, 108th, 112th, 116th, 120th, 124th, 128th.
Thor goes down the same hallway, putting one of his stickers on every fifth locker
Thor= 5th, 10th, 15th, 20th, 25th, 30th, 35th, 40th, 45th, 50th, 55th, 60th, 65th, 70th, 75th, 80th, 85th, 90th, 95th, 100th, 105th, 110th, 115th, 120th, 125th, 130th.
Common multiples of Janine fourth locker and Thor fifth locker= 20, 40, 60, 80, 100, 120
Therefore,
6 lockers have both students' stickers
