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 5 of 10.

Dibyansh Pattanaik said:   6 years ago
@All.

1. Why we subtracted QR or Why we deducted QR?
2. What would be the solution if the monthly income of Q is asked?

Please, anyone, clarify it.

Swapnil Andhale said:   6 years ago
Avg = sum/Number.

sum = avg*Number.

ie P+Q = 5050*2.
(2 is a no.of employees, candidate, etc . only P & Q is there ie. multiply it by 2).

Praveen said:   1 decade ago
Dude can we do like this ?
p+q=5050
q+r=6250
p+r=5200
p+q+q+r+p+r=16500
2(p+q+r)=16500
p+q+r=8250
hence p+q+r-(q+r)=p+q+r-q-r=>
p=8250-6250=4000

Aaditya said:   1 decade ago
If the average income of 10 persons is Rs. 21 and the average income of 150 persons is Rs. 25. Then find the average income of 50 persons.

Raghavendra said:   7 years ago
@Praveen.

The initial step wrong.

P+q=5050.
Q+r=6250.
P+r=5200.
Each value should multiply with 2 as it was average, not individual.

Reejesh said:   1 decade ago
Hi All,

Can this be done in this way?

Average of

(i) PQ = 5050.
(ii) QR = 6250.
(iii) PR = 5200.

Total 10250.
10250-6250 = 4000.

MIITAL said:   1 decade ago
p and Q = 5050.

Q and R = 6250.

P and R = 5200.

NOW TOTAL OF

P AND Q = 5050.

P AND R = 5200.

= 10250.

NOW(10250-6250) = 4000.

Sakshi Pandey said:   6 years ago
P + q= 5050*2=10100.
Q+r= 6250*2=12500.
P+r= 5200*4= 10400.

Monthly income of p = (q+r- (p+q+p+r))/2.
= (12500-10100+10400)/2=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?

Vikas said:   3 years ago
Work done by p,q is 5050.
Work done by q,r is 6250.


So,
6250 - 5050 = 1200,
ie 5200 - 1200=4000
Which is work done by P.
(52)


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