has several stamps of type A, and B has several stamps of type B. If B uses all the B stamps to exchange the same amount of A stamps with A, then B needs to replenish A with 320 points; if B does not make up the money, he has to exchange back 5 A stamps. It is known that the price of 3 stamps of type A is 48 cents less than that of 5 stamps of type B. How many stamps of type B does B have?
甲有A种邮票若干张，乙有B种邮票若干张．如果乙用所有的B种邮票向甲换数量同样多的A种邮票，则乙需要补给甲320分；如果乙不补钱，就要少换回5张A种邮票．已知3张A种邮票比5张B种邮票的价钱少48分，那么乙有B种邮票多少张？
<gadget id="calculator">320 / 5</gadget>
<output>64</output>

<gadget id="calculator">3 * 64</gadget>
<output>192</output>

<gadget id="calculator">192 + 48</gadget>
<output>240</output>

<gadget id="calculator">240 / 5</gadget>
<output>48</output>

<gadget id="calculator">64 - 48</gadget>
<output>16</output>

<gadget id="calculator">320 / 16</gadget>
<output>20</output>

<result>20</result>