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 8 of 10.

Lokesh patil said:   5 years ago
In simple words, 5050 + 5200 = 10250.

10250 - 6250 = 4000.
(17)

Vishesh said:   1 decade ago
@Praveen how did you get -(q+r) can you explain in detail?

Shree Hema said:   1 decade ago
Why we are multiplying every equation with 2 only in RHS?

Tin said:   1 decade ago
Why we need to subtract 6250? I can hardly understand.

Amandha said:   1 decade ago
Praveen is wrong why means 8250-6250=2000 not 4000.

Sanket bobde said:   6 years ago
Great experience and thank you all for explaining.

Likhita said:   8 years ago
Thanks @Tarun it's very excellent explanation.

Bhavna said:   8 years ago
Very nice way explanation thanks @Tarun.

Sunil said:   1 decade ago
Please help me for this 8250-6250= 4000.

Ratnakar said:   2 decades ago
It can also done as (i) + (iii) - (ii).


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