Answer:
12
Step-by-step explanation:
Probability = Expected outcome/Total outcome
GIven
Total outcome = 28marbles
probability of randomly drawing a blue marble = 3/7
Substitute
3/7 = number of blue marbles/28
Cross multiply
7N = 3* 28
N = 3*4
N= 12
Hence there 12 blue marbles in the bag
