Use mental math to solve the proportion. 25 over 40 equals 5 over t

t = 8

Step-by-step explanation:

create the proportion

simplifies down to

t = 8

5 black counters

Step-by-step explanation:

1/3 to sixths would equal two sixths. The problem already told us three of the siths, meaning the 15 are the other three sixths. Since 3/6 are half of the bag, then multiply 15 by two. Since there are 30 in all, and the bags are in thirds, you devide by three. Since 10 is the 1/3, you divide by 2 (10 by 2) since you multiply 1/3 to get the equivalant of 2/6. There are 5 black ones.

You could've also had done 30 divided by 6 to get 5 which is still the 1/6 of the bag.