Award: $10\mathrm{.}00$ points

The following table lists data from the budget of Ritewell Publishers. Half the company's sales are for cash immediately; the othe paid for with a one$-$month delay. The company pays all its credit purchases with a one$-$month delay. Credit purchases in January and total sales in January were $$220.$ Assume all expenses, other than purchases, are cash transactions.

$\backslash$table$[[$Total sales,February,March,April$],[$Purchases of materials,$$240,$$$260,$$$220$