Any multiple of 840.
LCM(3, 5, 7) = 105
Three and five-sevenths is the same as 26/7, so the reciprocal is 7/26.
21
21
7 pts
innocently
Any multiple of 140.
975
35 and all of its integral multiples
21 is the LCM since the numbers have no common factors except 1.
5, 7, and 3 go into 105.
840