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3. The number of pupils in Team A to the number of pupils in Team B is in the ratio 7:6. If 45 pupils are transferred from Team A to Team B, the ratio will become 2: 3. How many pupils are there in each team?​

User Rezna
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1 Answer

6 votes

Answers:

Team A = 175 people

Team B = 150 people

This is before the 45 students transfer from A to B.

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Step-by-step explanation:

x = number of people in team A

y = number of people in team B

These counts are before the 45 pupils transfer from A to B.

The counts are in ratio 7:6, which means,

x/y = 7/6

6x = 7y

x = 7y/6

If we subtract 45 people from team A, we have x-45 people left. Those 45 people go to team B to have y+45 pupils there.

The quantities x-45 and y+45 are in ratio 2:3, so,

(x-45)/(y+45) = 2/3

3(x-45) = 2(y+45)

3x-135 = 2y+90

3(7y/6)-135 = 2y+90 .... plug in x = 7y/6

21y/6 - 135 = 2y+90

6*( 21y/6 - 135 ) = 6*(2y+90)

21y-810 = 12y+540

21y-12y = 540+810

9y = 1350

y = 1350/9

y = 150

x = 7y/6

x = 7(150)/6

x = 175

We have 175 people on team A, and 150 people on team B.

This is before the 45 students transfer from A to B.

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Check:

x/y = 175/150 = (7*25)/(6*50) = 7/6

This shows x and y are in ratio 7:6 to match the instructions.

x-45 = 175-45 = 130

y+45 = 150+45 = 195

(x-45)/(y+45) = 130/195 = (2*65)/(3*65) = 2/3

And we have the updated counts in the ratio 2:3, which matches the stated info in the instructions. The answers are fully confirmed.

User Rschlachter
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