Length of four pipes are 28 m, 42m , 84m and 133m respectively and to be cut into pieces of equal length, find the least number of pieces that can be obtained .
Least number of pieces = (28 ÷ 7) + (42 ÷ 7) + (84 ÷ 7) + (133 ÷ 7) = 4 + 6 +12 + 19 = 41