1) marbles altogether = 3+4=7
P(black) = 3/7
2) P(first black marble)= 3/7
second black marble - When you removed 1st one only 2 black marbles are left and altogether marbles that are left = 6
P(second black marble) = 2/6=1/3
P(2 black marbles without replacement) means black and black marbles without replacement.
P(2 black marbles without replacement) =3/7*1/3=1/7
3) P(first black marble)= 3/7
When you put that black marble back, you got again <span>3 black marbles and 4 red marbles in a bag. So,
</span> P(second black marble)= 3/7
P(2 black marbles with replacement)=3/7*3/7= 9/49<span>
</span>
Answer:
#1- 7x*2=14x, the rest = 7x
Step-by-step explanation:
Answer:
The perimeter of a circle is π × d. Here's is the diameter of the circle. Hence, the perimeter of a circle is half of that of the circle that is ½ π × d.
The area of a circle is pi times the radius squared (A = π r²). Learn how to use this formula to find the area of a circle when given the diameter.
Step-by-step explanation:
Answer: 
Step-by-step explanation:
1. If you join the top part and the bottom part of the figure, you obtain a sphere. Then, you must apply the formula for calculate the surface area of a sphere:
Where r is the radius (
)
2. Then:
3. The formula for calculate the suface area of the red part, which is a cylinder, is:
Where h is the height (h=32mm)
4. Then:
5. So, the total surface area is:
