he positive integers from 1 to 150 inclusive are placed in a 10 by 15 grid so that each cell contains exactly one integer. Then the multiples of 3 are given a red mark, the multiples of 5 are given a blue mark, and the multiples of 7 are given a green mark. How many cells have more than 1 mark?

10

12

15

18

19

idk which one

Guest May 30, 2021

#1**+1 **

3 x 5 = 15 so all multiles of 15 are marked with two = 10

3*7 = 21 all multiples of 21 (105 already marked) = 6

5x7 = 35 35 70 105 and 140 (but 105 already marked) = 3 total 19

ElectricPavlov May 30, 2021