Answer:
456
Step-by-step explanation:
Procedure:
1) calculate the number of diferent teams of four members that can be formed (with the ten persons)
2) calculate the number of teams tha meet the specification (two girls and two boys)
3) Divide the positive events by the total number of events: this is the result of 2) by the result in 1)
Solution
1) the number of teams of four members that can be formed are:
10*9*8*7 / (4*3*2*1) = 210
2) Number of different teams with 2 boys and 2 girls = ways of chosing 2 boys * ways of chosing 2 girls
Ways of chosing 2 boys = 6*5/2 = 15
Ways of chosing 2 girls = 4*3/2 = 6
Number of different teams with 2 boys and 2 girls = 15 * 6 = 90
3) probability of choosing one of the 90 teams formed by 2 boys and 2 girls:
90/210 = 3/7
Answer:
D) 54 cm
Step-by-step explanation:
We can use the Centroid Theorem to solve this problem, which states that the centroid of a triangle is 
of the distance from each of the triangle's vertices to the midpoint of the opposite side.
Therefore, 
is of the distance from 
to 
, since the latter is the midpoint of the side opposite to . We know this because belongs to 
, so must be 
's midpoint due to the fact that by definition, the centroid of a triangle is the intersection of a triangle's three medians (segments which connect a vertex of a triangle to the midpoint of the side opposite to it).
We can then write the following equation:
Substituting 
into the equation gives us:
Solving for , we get:
(Multiply both sides of the equation by 
to get rid of 's coefficient)
(Simplify)
(Symmetric Property of Equality)
Therefore, the answer is D. Hope this helps!
