1/15+4/15+1/18+5/18+2/21+5/21+1/24+7/24=

Решим заданный пример:1/15 + 4/15 + 1/18 + 5/18 + 2/21 + 5/21 + 1/24 + 7/24 = ?1) 1/15 + 4/15 = 5/15 = 1/3,2) 1/18 + 5/18 = 6/18 = 1/3,3) 2/21 + 5/21 = 7/21 = 1/3,4) 1/24 + 7/24 = 8/24 = 1/3,5) 1/3 + 1/3 + 1/3 + 1/3 = 4/3 = 1 1/3.Значит, 1/15 + 4/15 + 1/18 + 5/18 + 2/21 + 5/21 + 1/24 + 7/24 = 1 1/3.