What is a multiple of both 3 and 7?

Answer 1

A multiple of both 3 and 7 is a number that can be evenly divided by both 3 and 7 without leaving a remainder. To find the least common multiple of 3 and 7, you can simply multiply the two numbers together since 3 and 7 are prime numbers and have no common factors other than 1. Therefore, a multiple of both 3 and 7 would be 21.

Answer 2

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, ...