ardz24 wrote:A certain ball team has an equal number of right- and left-handed players. On a certain day, two-thirds of the players were absent from practice. Of the players at practice that day, one-third were left handed. What is the ratio of the number of right-handed players who were not at practice that day to the number of left handed players who were not at practice?
A. 1/3
B. 2/3
C. 5/7
D. 7/5
E. 3/2
This is an EITHER/OR group question.
Each player is EITHER left-handed OR right-handed.
Each player is EITHER present OR absent.
For an EITHER/OR group problem, use a GROUP GRID to organize the data.
Let L = left-handed, R = right-handed, P = present, A = absent.
To get a good number for the total, multiply all of the DENOMINATORS of the fractions described in the problem.
An equal number of left-handed and right-handed players implies 1/
2.
2/
3 were absent.
Of the players who attended practice, 1/
3 were left-handed.
Let the total =
2*3*3 = 18.
Here's the grid:
_______________L_______R_______Total
P:
A:
total:____________________________18
Now let's fill in the grid step by step.
As soon as we know 2 entries in a row or a column, we can calculate the remaining entry in that row or column.
A certain ball team has an equal number of right- and left-handed players.
Two-thirds of the players were absent from practice.
_______________L_______R________Total
P:________________________________6
A:_______________________________12
total:__________9_______9_________18
Of the players at practice that day, one-third were left handed.
_______________L______R________Total
P:_____________2______4___________6
A:_______________________________12
total:__________9______9__________18
Complete the grid:
_______________L______R_________Total
P:_____________2______4__________6
A:_____________7______5_________12
total:__________9______9_________18
Answer the question:
(right-handed and absent)/(left-handed and absent) = 5/7.
The correct answer is
C.
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