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
+36915 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
