The number of students in 3 classes is in the ratio 2 : 3 : 4. If 12 students are increased in each class this ratio changes to 8 : 11 : 14. The total number of students in the three classes in the beginning was
A. 162
B. 108
C. 96
D. 54
Answer: Option A
Solution(By Examveda Team)
Let the number of students in the classes be 2x, 3x and 4x respectively; Total students = 2x + 3x + 4x = 9x $$\eqalign{ & {\text{According}}\,{\text{to}}\,{\text{the}}\,{\text{question}}, \cr & \frac{{ {2x + 12} }}{{ {3x + 12} }} = \frac{8}{{11}} \cr & or,\,24x + 96 = 22x + 132 \cr & or,\,2x = 132 - 96 \cr & or,\,x = \frac{{36}}{2} = 18 \cr & {\text{Hence,}} \cr & {\text{Original}}\,{\text{number}}\,{\text{of}}\,{\text{students}}, \cr & 9x = 9 \times 18 \cr & \,\,\,\,\,\,\,\, = 162 \cr} $$Join The Discussion
Comments ( 8 )
Related Questions on Ratio
If a : b : c = 3 : 4 : 7, then the ratio (a + b + c) : c is equal to
A. 2 : 1
B. 14 : 3
C. 7 : 2
D. 1 : 2
If $$\frac{2}{3}$$ of A=75% of B = 0.6 of C, then A : B : C is
A. 2 : 3 : 3
B. 3 : 4 : 5
C. 4 : 5 : 6
D. 9 : 8 : 10
Wow
Easy guys take two ratio
2 : 3
+12 +12
8 : 11
Cross multi and sub
8×3-11×2 = 11×12-8×12
2=36
1=18
Total origina sum 9×18 =162
where is 4+12??
Why we not consider 14?
ye kese hoa ...??
24x+96 = 22x+132
Or, 2x = 132-96
Or, x = 36/2 = 18
Hence, Original number of students,
9x = 9*18 = 162.
Any essy mathed.. Its very hard
Cross-multiplication has been done.
(2x+12)/(3x+12) = 8/11
11*(2x+12) = 8 *(3x+12)
24x+96 = 22x+132
i didn't understand from where it comes 24x+96 = 22x+132