Sheila, Purity, and Rose want to rent a house. Sheila has offered to pay five times Purity’s share of the rent. Rose can only afford thrice what Purity pays. If Rose’s share is $1,800, what is the total house rent?
Purity will pay a third of Rose's share, which translates to 1800/3 = 
<gadget id="calculator">1800/3</gadget>
<output>600</output>
600 dollars.
Sheila has offered to pay 5 * 600 = 
<gadget id="calculator">5*600</gadget>
<output>3_000</output>
3000 dollars.
Combining everyone's share of the rent will give a total of 600 + 3000 + 1800 = 
<gadget id="calculator">600+3000+1800</gadget>
<output>5_400</output>
5400 dollars.

<result>5_400</result>