What is the lowest total resistance that can be secured by combinations of four coils of resistance `4Omega,8Omega,12Omega,24Omega`

Explanation

(a) Highest ( by connecting in series )
= 4+ 8 + 12 +24
series = `48 Omega`
(b) Lowest ( by connecting ) in parallel =
`(1)/(R_(p))= (1)/(4) + (1)/(8) +(1)/(12)+(1)/(24)`
`=(12)/(24) `
`(1)/(R_(p))=(1)/(2)`
`R_(p)=2 Omega`