Staphyk wrote:
Hello Karishma ,
Kindly help me with this question ,am confused
and don’t know where to start from
In the county of Veenapaniville, there are a total of 50 high schools, of three kinds: 25 public schools, 16 parochial schools, and 9 private independent schools. These 50 schools are divided between three districts: A, B, and C. District A has 18 high schools total. District B has 17 high schools total, and only two of those are private independent schools. If District C has an equal number of each of the three kinds of schools, how many private independent schools are there in District A?
Sent from my iPhone using
GMAT Club Forum mobile appLEt's make a 3*3 matrix here:
.................................................. A ......... B ........... C........... Total
Public School...........................................................................25
Parochial School......................................................................16
Private Independent School......................2...............................9
Total.........................................18..........17.............................50
Step 2: C has equal number of the 3 school types
.................................................. A ......... B .............. C......................... Total
Public School..............................................................5...........................25
Parochial School.........................................................5...........................16
Private Independent School......................2.................5...........................9
Total.........................................18..........17.......
50-18-17=15.................50
Step 3: No of private independent schools in district A
.................................................. A ......... B .............. C......................... Total
Public School..............................................................5...........................25
Parochial School.........................................................5...........................16
Private Independent School.......
9-2-5.......2.................5...........................9
Total.........................................18..........17...............15.................50
Answer: A has 2 private independent schools
Alternatively,
All you need to do is focus on what you need. You need to find the number of private schools in A. Total no. of private schools is 9 and in B, you have 2 of them. So there are 7 private schools distributed between A and C. All you need to find is the number of private schools in C to get the number of private schools in A. What is given to you about C? C has an equal number of each of the three kinds of schools. Total number of schools in C = 50 - (18 + 17) = 15. So no. of private schools in C = 15/3 = 5
Therefore, A must have 7 - 5 = 2 private schools.