There are 4 white balls and 2 red balls in the bag. Take two balls from the bag, one ball at each time, observe the color and put it back. Of the 2 balls taken, what is the probability that one is white and the other is red?
袋中有4只白球、2只红球，从袋中取两次球，每次任取1只，观察颜色后放回．取到的2只球，1只是白球1只是红球的可能性是多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>