Can You Help Me With Science please????

Question

There are sources of resistance in a parallel circuit. Two of them are rated at 20 ohms, the other at 10 ohms. What is the circuits total resistance?

a) 20 ohms
b)12 ohms
c) 8 ohms
d) 5 ohms

Answer 1

If the resistances are (say) R1,R2 and R3,

In parallel, the equivalent resistance (say) R is given by,
1/R=1/R1+1/R2+1/R3. So,
R=[(R1*R2)+(R2*R3)+(R3*R1)]/(R1*R2*R3)
In series, R=R1+R2+R3

Answer 2

that would be 1/20 +1/20+1/10 add together and invert the answer
2 ea 20 in parallel = 10 ohms.
10 in parallel with 10 =5ohms.

Answer 3

its 5 ohms
if want to know how?

every similar two res. in parallel result the half value

so 20 // 20 = 10
10//10 = 5

Answer 4

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