AFCAT Model Paper 2

Given∶
Ratio of water and HCL in test tube A = 7 ∶ 11
Formula Used∶
Simple concept of ratios.
a ∶ b can be written as ax and bx where x is a positive integer. Calculation∶
Ratio of water and HCL in test tube = 7 ∶ 1
So, the total volume of test tube A = 7a + 11a = 18a, where a is a positive integer.
Ratio of water and HCL in test tube B = 13 ∶ 23
So, the total volume of test tube B = 13b + 23b = 36b, where b is a positive integer.
It is also given that,
Volume of test tube A = Volume of test tube B
18 a = 36 b
⇒ a = 2 b
Total Volume of water in test tube C=7a+13b=7(2b)+13b=27b
Total Volume of HCL in test tube C=11a+23b=11(2b)+23b=45b
Thus, Ratio of water to HCL in test tube C=

27b

45b

=

3

5

=3∶5
∴ The final ratio of water and HCL in test tube C is 3 ∶ 5.