The number of students in 3 classes is in the ratio 2:3:4. If 12 stude...
162
Let number of students in the classes be
2x, 3x and 4x respectively; then
total students= 2x+3x+4x=9x.
According to question, (2x+12)/ (3x+12) = 8/11
⇒ 24x+96=22x+132
2x= 132 – 96
⇒ x= 36/2= 18
Hence, original number of students,
= 9x= 9 × 18=162.
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The number of students in 3 classes is in the ratio 2:3:4. If 12 stude...
To solve this problem, we can set up a proportion using the ratios given in the problem. Let's say the number of students in the three classes initially is 2x, 3x, and 4x.
Given:
The ratio of the number of students in the three classes initially is 2:3:4
So, the number of students in the three classes initially can be written as 2x, 3x, and 4x.
The ratio of the number of students in the three classes after an increase of 12 students in each class is 8:11:14
So, the number of students in the three classes after the increase can be written as (2x + 12), (3x + 12), and (4x + 12).
Now, we can set up a proportion using the two ratios:
(2x + 12) : (3x + 12) : (4x + 12) = 8 : 11 : 14
To solve this proportion, we can cross-multiply:
8(3x + 12) = 11(2x + 12)
24x + 96 = 22x + 132
24x - 22x = 132 - 96
2x = 36
x = 36/2
x = 18
So, the number of students in the three classes initially is:
2x = 2(18) = 36
3x = 3(18) = 54
4x = 4(18) = 72
Therefore, the total number of students in the three classes in the beginning was:
36 + 54 + 72 = 162
Hence, the correct answer is option A) 162.
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