Question 147 of 380

The series combination of two batteries, both of the same emf $10V,$ but different internal resistance of $20 \Omega$ and $5 \Omega ,$ is connected to the parallel combination of two resistors $30 \Omega$ and $\text{x}\Omega .$ The voltage difference across the battery of internal resistance $20 \Omega$ is zero, the value of $\text{x}$ (in $\Omega )$ is____