Q21. 
On a certain day, the ratio of the passenger in the 1st class and the second class travelling by train is $1:3$. the ratio of the fares collected from each first class and second class passengers is $30:1$. If the total amount collected from all the passengers is Rs 1,320. Find the amount in Rs, collected from the second class passengers. 
A.  240 

B.  360 

C.  480 

D.  120 
Q22. 
By mistake, instead of dividing Rs 117 among three persons $P$, $Q$ and $R$ in the ratio $\left(\dfrac{1}{2}, \dfrac{1}{3},\dfrac{1}{4}\right)$, it was divided in the ratio $2:3:4$. Who gains the most and how much? 
A.  $P$, Rs 28 

B.  $Q$, Rs 35 

C.  $R$, Rs 25 

D.  $R$, Rs 27 
Q23. 
$20%$ of the students in a class failed in an examination. Out of the students who failed, $75%$ were males. Male students who failed constitute $90%$ of the economically poor students in the class. What is the ratio of the number of economically poor students to the number of students in the class? 
A.  $1:4$ 

B.  $1:5$ 

C.  $5:6$ 

D.  $1:6$ 
Q24. 
The present ages of $A$ and $B$ are as $6:4$. Five years ago their ages were in the ratio $5:3$. Find their present ages. 
A.  42, 28 

B.  36, 24 

C.  30, 20 

D.  25, 15 
Q25. 
$A$, $B$ and $C$ enter into a partnership by investing Rs.3600, Rs.4400 and Rs.2800. $A$ is a working partner and gets a fourth of the profit for his services and the remaining profit is divided amongst the three in the rate of their investments. What is the amount of profit that $B$ gets if $A$ gets a total of Rs. 8000? 
A.  4888.88 

B.  9333.33 

C.  4000 

D.  3666.66 