Ivanhoe, Inc. estimates the cost of its physical inventory at March $31$ for use in interim financial statements. Ivanhoe's rate of markup on cost is $20\%.$ The following account balances are available at March $31$:

Inventory, March $1$$$540000$

$\backslash$table$[[$Purchases$,420000],[$Purchase returns,$10000],[$Sales during March,$720000]]$

The estimate of the cost of inventory at March $31$ would be

$$230000.$

$$240000.$

$$350000.$

$$386000.$