Question

Bag A contains 2 black marbles and 3 white marbles. Bag B contains 5 black marbles and 8 white marbles. Sarah adds some marbles to bag B, the probability of picking a black marble at random from either bag is now the same. Work out the smallest number of black marbles and white marbles he adds to bag B

Answer 1

add one black and one white marble

Explanation:

you have to make bag b equivalent to a 2:3 ratio.

add 1 to 5 to make it divisible by 2

divide 6 by 2

=3

multiply 3 by 3 to get a 2:3 ratio

=9

subtract initial marbles

9-8=1