Question

Tính :

a) 5 / 6 x 6 / 7 x 7 / 8 : 15 / 16

b) 4 / 7 x 7 / 10 x 3 / 4 : 9 / 20

Answer 1

b)\(=\frac{4x7x3}{7x10x4}x\frac{20}{9}\\ =\frac{3}{10}x\frac{20}{9}\\ =\frac{2}{3}\)

Answer 2

\(\frac{5}{6}\times\frac{6}{7}\times\frac{7}{8}:\frac{15}{16}\)

\(=\frac{5}{6}\times\frac{6}{7}\times\frac{7}{8}\times\frac{16}{15}\)

\(=\frac{1}{1}\times\frac{1}{1}\times\frac{1}{1}\times\frac{2}{15}\)

\(=\frac{2}{15}\)

Answer 3

\(\frac{4}{7}\times\frac{7}{10}\times\frac{3}{4}:\frac{9}{20}\)

\(=\frac{4}{7}\times\frac{7}{10}\times\frac{3}{4}\times\frac{20}{9}\)

\(=\frac{4}{1}\times\frac{1}{10}\times\frac{1}{1}\times\frac{5}{3}\)

\(=\frac{4}{10}\times\frac{5}{3}\)

\(=\frac{4}{2}\times\frac{1}{3}\)

\(=\frac{4}{6}\)

\(=\frac{2}{3}\)