Three resistors `2 Omega, 4 Omega` and `5 Omega` are combined in parallel. What is the total resistance of the combination?

Explanation

Here `R_(1) = 2 Omega, R_(2) = 4 Omega, R_(3) = 5 Omega, V = 20 V`
In parallel combination total resistance `R_(P)` is given by
`(1)/(R_(P)) = (1)/(R_(1)) + (1)/(R_(2)) + (1)/(R_(3)) = (1)/(2) + (1)/(4) + (1)/(5) = (10 + 5 + 4)/(20) = (19)/(20)` or `R_(P) = (20)/(19) Omega`