By definition devices are in parallel when they share a common voltage, V. So we can write I = V/R where R is the effective resistance and I is the circuit's total amperage. We can define R in more detail by noting I = SUM(i) = SUM(V/r) = V SUM(1/r) where each r is a device in the parallel circuit. So we see that 1/R = SUM(1/r) = 1/r + 1/r + ... + 1/r for 37 times or SUM(1/r) = 37/r = 37/330 = 1/R and R = 330/37 as the AMfox shows. But now you know why.
Answers & Comments
Resistance will be 330/n= 330/37=8.9 ohms
By definition devices are in parallel when they share a common voltage, V. So we can write I = V/R where R is the effective resistance and I is the circuit's total amperage. We can define R in more detail by noting I = SUM(i) = SUM(V/r) = V SUM(1/r) where each r is a device in the parallel circuit. So we see that 1/R = SUM(1/r) = 1/r + 1/r + ... + 1/r for 37 times or SUM(1/r) = 37/r = 37/330 = 1/R and R = 330/37 as the AMfox shows. But now you know why.
The total resistance can be determined by 1/R = 1/330 + 1/330 + ... + 1/330
So 1/R = 37/330, and therefore R = 330/37 = 8.919 ohms.