All multiples of their lowest common multiple (which is 71), so pick any one you like from:
21, 42, 63, 84, 105, 126, 147, 168, 189, 210, 231, 252, 273, 294, 315, 336, 357, 378, 399, 420, 441, 462, 483, 504, 525, 546, 567, 588, 609, 630, 651, 672, 693, 714, 735, 756, 777, 798, 819, 840, 861, 882, 903, 924, 945, 966, 987, 1008, 1029, 1050, 1071, 1092, 1113, 1134, 1155, 1176, 1197, 1218, 1239, 1260, 1281, 1302, 1323, 1344, 1365, 1386, 1407, 1428, 1449, 1470, 1491, 1512, 1533, 1554, 1575, 1596, 1617, 1638, 1659, 1680, 1701, 1722, 1743, 1764, 1785, 1806, 1827, 1848, 1869, 1890, 1911, 1932, 1953, 1974, 1995, 2016, 2037, 2058, 2079, 2100, ...
42
Both 21 and 42 will work. ■
14 = 2 X 7 42 = 2 X 3 X 7 So 2 & 7 are common to both multiples / NB '3' is NOT a common multiple.
No but 21 is a multiple of 3 because 7*3 = 21
The least common multiple of 2 , 3 , 7 = 42
The (LCM) Least Common Multiple of 7 and 3 is 21 because that is the LEAST number that both 3 and 7 go into.
The (LCM) Least Common Multiple of 7 and 3 is 21 because that is the LEAST number that both 3 and 7 go into.
42
The only number that could be both a factor and a multiple is 7 itself.
Both 21 and 42 will work. ■
14 = 2 X 7 42 = 2 X 3 X 7 So 2 & 7 are common to both multiples / NB '3' is NOT a common multiple.
21 is the smallest number that both 7 and 3 divide into evenly with no remainder.
21, 42, 63, 84, 105, 126 . . . infinity.
There is no such number. Since if x were the largest multiple of 3 and 7 then what about 2x? 2x would be a multiple of 3 since x is a multiple of 3; 2x would be a multiple of 7 since x is a multiple of 7; and 2x is bigger than x. So x cannot be the largest.
21 is a multiple of 7 because, 3*7 = 21
Because 18*7 = 126 and 42*3 = 126 126 is a multiple of both, 18 and 42, and so it is their common multiple.
It's a multiple of 7 (17 x 7) but not 3 (the digits 119 don't add up to 3)