Two vessels separately contain two ideal gases A and B at the same temperature. The pressure of gas A is three times the pressure of gas B. Under these conditions, the density of gas A is found to be two times the density of B. The ratio of molecular weights of gas A and B, i. e. \(\rm \frac{M_A}{M_B}\) is
1
\(\rm \frac{2}{3}\)
2
\(\rm \frac{3}{2}\)
3
\(\rm \frac{3}{4}\)
4
\(\rm \frac{4}{3}\)