John has 50 fliers remaining. If you think about it, he already put up 10 because John put up 1 over 5 and 2 over 5. So 75- 10=65. Now, John put 1 over 5 of them. That is 1 x 5=5. Next, you subtract 65-5 and that is 60. John put 2 fliers over 5 of them so, that is 2 x 5, or 10. 60 - 10 is 50 fliers.