Question #a83d6

1 Answer
Aug 6, 2017

#2#

Explanation:

Without removing any white chips, the probability of picking a black chip is

#P("black chip") = "black chips" / "total chips" = 8/(8+6)=8/14#

When we remove the white chips, only the total number of chips will decrease in number. That is, there will always be #8# black chips.

Since we want the probability of picking a black chip to equal #2/3#, we can set up the following equation:

#2/3 = 8/ x#

where #x# is the total number of chips in the box.

We can now cross-multiply and solve for #x#:

#2x = 8 * 3#

#2x = 24#

#x = 12#

Thus, once we have #12# chips, the probability of picking a black chip will be #8/12#, which simplifies to #2/3#.

Since we started with a total of #14# chips, we have removed #color(red)2# white chips to get a total number of #12# chips.