This can be done in more than one way, but i like the simpler way, so i will show you that. The simplest way to do this is to simplify the equation into a simpler way to do it. If you have 40%, that's hard to get to 100%, so divide it by 4. You will get 36, and that is now 10% of the unknown number. Then just multiply 36 by 10 and you get 360, which is your final number.
Hope this helped, please mark brainliest i need to feed my family ^_^
If resistors are in series, so the current is the same in all of them. In this problem we have four resistors. So, we can get a relationship between the Equivalent resistance of series combination and the four resistors as follows: