Not all multiples of 40 are multiples of 80. Only the even multiples of 40 are also multiples of 80. The odd multiples, e.g. 40, 120, 200, 280, and 360, are not multiples of 80.
First multiples of 80 are 1 and 80
The multiples of 16 are 16, 32, 48, 64, 80, etc. The multiples of 20 are 20, 40, 60, 80, 100, etc. The common multiples of 16 and 20 are 80, 160, 240 and so on.
The multiples of 80 are: 80, 160, 240, 320, 400, 480, 560, 640, 720, 800, 880, & 960.
80
63 and 72 are the only two multiples of 9 between 60 and 80.
80 160 240 320 400 480
The first four multiples of 20 are: 20 40 60 80
The first ten positive integer multiples of 80 are: 1 x 80 = 80 2 x 80 = 160 3 x 80 = 240 4 x 80 = 320 5 x 80 = 400 6 x 80 = 480 7 x 80 = 560 8 x 80 = 640 9 x 80 = 720 10 x 80 = 800
1,2,5,10
Multiples of 240
The factors of 80 are: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80 Those which are multiples of 4 are: 4, 8, 16, 20, 40, 80