Trim one of the resistors to 18R, then throw the rest in your parts bin for later.

https://hackaday.com/2017/04/10/hackaday-trims-its-own-resistors/

Or, assuming they're 10% resistors, find the ones that are on the low end (27R) and put two in series, putting that in parallel with one 27R. Put the last one in your parts bin for later.

^{simulate this circuit – Schematic created using CircuitLab}

Put two in parallel, trim them resistors to 18R, then throw the rest in your parts bin for later.

https://hackaday.com/2017/04/10/hackaday-trims-its-own-resistors/

Or, assuming they're 10% resistors, find the ones that are on the low end (27R) and put two in series, putting that in parallel with one 27R. Put the last one in your parts bin for later.

^{simulate this circuit – Schematic created using CircuitLab}

Trim one of the resistors to 18R, then throw the rest in your parts bin for later.

https://hackaday.com/2017/04/10/hackaday-trims-its-own-resistors/

Trim one of the resistors to 18R, then throw the rest in your parts bin for later.

https://hackaday.com/2017/04/10/hackaday-trims-its-own-resistors/

Or, assuming they're 10% resistors, find the ones that are on the low end (27R) and put two in series, putting that in parallel with one 27R. Put the last one in your parts bin for later.

^{simulate this circuit – Schematic created using CircuitLab}