Aptitude - Average - Discussion

Discussion Forum : Average - General Questions (Q.No. 7)
7.
The average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is:
3500
4000
4050
5000
Answer: Option
Explanation:

Let P, Q and R represent their respective monthly incomes. Then, we have:

P + Q = (5050 x 2) = 10100 .... (i)

Q + R = (6250 x 2) = 12500 .... (ii)

P + R = (5200 x 2) = 10400 .... (iii)

Adding (i), (ii) and (iii), we get:  2(P + Q + R) = 33000  or   P + Q + R = 16500 .... (iv)

Subtracting (ii) from (iv), we get P = 4000.

P's monthly income = Rs. 4000.

Discussion:
93 comments Page 6 of 10.

Bhanu ravali said:   1 decade ago
P + Q + = 10100.

+ Q + R = 12500.

---------------

P + 2Q + R = 22600.

P + + R = 10400 (subtraction).

--------------

2Q = 12200.

Q = 6100.

P + Q = 10100.

P = 10100 - 6100.

= 4000.

Pranav said:   9 years ago
Think Logically.

Given Data:

P and Q = 5050.
Q and R = 6250.
P and R = 5200.

Solution:

Take common point = (Q and R) - (P and R).
(6250) - (5200) = 1050 -----> equation 1.

Now,
(P and Q) - (equation 1).
(5050) - (1050) = 4000.

So, the Answer is 4000.

Vipin said:   9 years ago
The quickest method is :

(p and q) + (p and r) - (q and r).
5050 + 52000 - 6250.
10250 - 6250.

Answer is = 4000.

Aman Dewangan said:   9 years ago
It can be solved directly:

(p+q) = (2*5050).....(1)
(p+r) = (2*5200).....(2)

We want to get value of p.

So,

Add eq (1 & 2)

=> 2p+(q+r) = 20500....(3)
=> As (q+r) = (2*6250) is given,

Put this in eq.(3).

2p = 20500-12500,
2p = 8000,
p = 4000.

Amani said:   9 years ago
Easily explained @Yesu Babu.

Pema wangcan said:   9 years ago
Its simple, what we have to do is concentrate on what was the logic behind the question see.

They have already given the average of PQ =5050, QR=6250 and PR=5200. But we have to see the income of P only, therefore average means individual share for P he has 5050 + 5200 = 10250.
But see here. The share of P was shared by both R and Q which means P has to get his share. And we have to deduct 6250. (10250 - 6250) = 4000.

Kayalvizhi said:   9 years ago
p + Q = 5050
Q + R = 6250
P + R = 5200

(P + Q) - (Q + R) = 1200.

Now 5200 - 1200 = 4000.

I done like this is correct way or not?

SAM said:   9 years ago
Average of P and Q means (P + Q/2) = 5050.

Then it becomes, 2 goes that side.

P + Q = (5050 x 2) = 10100, Eq ---> (i).

Average of Q and R means Q + R/2.

Q + R = (6250 x 2) = 12500, Eq ---> (ii).

P + R/2.

P + R = (5200 x 2) = 10400, Eq ---> (iii).

Adding (i) , (ii) and (iii) , we get: 2 (P + Q + R) = 33000 or P + Q + R = 16500, Eq ---> (iv).

Subtracting (ii) from (iv), we get P = 4000.

P's monthly income = Rs. 4000.

RECHU said:   9 years ago
SIMPLY
P + Q + R = 16500.
P + 12500 = 16500.
P = 16500 - 12500.
P = 4000.

Asmara said:   9 years ago
Why we subtract total from equation (ii) as that is a monthly income of Q+R. How we can assume it's P's monthly income while there is No written P, Please explain.


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