Answer:
Total number of marbles = 10+20+30 = 60 out of which 20 are blue.
Probability of first marble being blue = 20/60
Probability of second marble being blue = 19/59
Probability of third marble being blue = 18/58
Probability of fourth marble being blue = 17/57
Probability of fifth marble being blue = 16/56
So probability of all marble being blue when five marbles are drawn from the box = (20/60)*(19/59)*(18/58)*(17/57)*(16/56) = 34/11977 = 0.00283877432
Step-by-step explanation:
Think of the entire population of 6th graders here. 3/7 are boys and 4/7 are girls. 5/8 of these boys are in Ms. Jones' class; that fraction would be (5/8)(3/7), or 15/56. This 15/56 represents the fraction of the entire sixth grade class who are in Ms. Jones' class.
Answer:
20 + 10 = blank × (4 + 2)
30 = blank × 6
blank = 30 ÷ 6 = 5