a) Ta có: \(\frac{{20}}{{100}} = \frac{1}{5}\) nên \(20kg = \frac{1}{5}\) tạ
\(\frac{{20}}{{1000}} = \frac{1}{{50}}\) nên 20 kg = \(\frac{1}{{50}}\) tấn
b) Ta có:
\(\frac{{55}}{{100}} = \frac{{55:5}}{{100:5}} = \frac{{11}}{{20}}\)
nên \(55kg = \frac{{11}}{{20}}\) tạ
\(\frac{{55}}{{1000}} = \frac{{11}}{{200}}\) nên 55kg = \(\frac{{11}}{{200}}\) tấn
c) Ta có:
87 kg = \(\frac{{87}}{{100}}\) tạ
87kg = \(\frac{{87}}{{1000}}\) tấn
d) Ta có:
91kg = \(\frac{{91}}{{100}}\) tạ
91kg = \(\frac{{91}}{{1000}}\) tấn