Question

Three resistors of 10, 15 and 5 are connected in parallel. Find their equivalent resistance.

Answer 1

the formula is
1/equivalent resistance =1/r1+1/r2+1/r3
so =>1/10/1/15+1/5=3+2+6/30=11/30
so equivalent resistance =30/11=2.7ohm

Answer 2

Let Equivalent Resistance in parallel be Rp
We know,
1/Rp = 1/R1 + 1/R2 + 1/R3 +..... + 1/Rn
1/Rp = 1/10 + 1/15 + 1/5
1/Rp = (3+2+6)/30  [LCM of 10,15,5 is 30]
1/Rp = 11/30
Rp = 30/11 Ω
Rp = 2.7272 Ω

Hope this is the required answer.
Good luck, friend! : )