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brajeshc
vmelgargalan
1050 + 5x = 1550 + 5y

5x - 5y = 500

(Divide both sides by 5)

x - y = 100

Only two digits were x - y = 100 is 130 and 30

If this is the case it will match numbers in a year or so ..

1050+1050*1.30 and 1550+1550*.3 ....

In my opinion 40 and 30 should be Answer


It is said that after 5 years, the number of employees in organization A will be equal to the number of employees in organization B.
If we take 40 and 30 then after 5 years, the result will be :

Org A : 1,050 + (40*5) = 1,250

Org B : 1,550 + (30*5) = 1,700

It doesn't match, so it can't be our answers.

However, if you take 130 and 30 :

Org A : 1,050 + (130*5) = 1,700

Org B : 1,550 + (30*5) = 1,700

It's a match !


Answers : 130 and 30.
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1050+5x=1550+5y
x-y=100

Only 130 and 30 suffice :)
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Whats the OA? Shouldnt the andwer be A>40 and B>30 ?
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Whats the OA? Shouldnt the andwer be A>40 and B>30 ?

OA is updated

Organization A: 130
Organization B: 30

Thank you!
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Why do we solve by means of an arithmetic progression and not a geometric prgression?

What I initially did was 1050*a^5 = 1550*b^5. a and b being A and B respective constant rates.
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Rogerper123
Why do we solve by means of an arithmetic progression and not a geometric prgression?

What I initially did was 1050*a^5 = 1550*b^5. a and b being A and B respective constant rates.
I absolutely agree with you, even I tried solving it using a GP.
Just saying " constant annual rate of member increase " is AMBIGUOUS. As it can mean both:
1. constant additive growth or linear growth OR
2. constant percentage increase or compound growth

BUT!!!

NOTICE THE UNITS GIVEN IN THE TABLE.
"Rate of increase (members per year)"
Now if I say organization increases with a constant rate, it does clearly means increase in members per year is constant, and hence in AP or linear growth.

I hope this helps
(PS" even I stayed frustrated by this question for a long time)
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is my approach correct ?

Initally they have difference of 1550-1050 = 500 in b/w them and this 500 needs to be covered in 5 yrs and since rates are same so each year they will cover 500/5 = 100 ka difference
now, since A surpasses B afterwards so A's rate is more than B and only 130 and 30 can be valid options since only then the difference of 100 in a year can be covered
A moved ahead by 130, B moved ahead by 30 so overall difference b/w is 100
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djangobackend
is my approach correct ?

Initally they have difference of 1550-1050 = 500 in b/w them and this 500 needs to be covered in 5 yrs and since rates are same so each year they will cover 500/5 = 100 ka difference
now, since A surpasses B afterwards so A's rate is more than B and only 130 and 30 can be valid options since only then the difference of 100 in a year can be covered
A moved ahead by 130, B moved ahead by 30 so overall difference b/w is 100
Yes, Your approach is correct as well, and it works because of the constant additive rates.
To clarify it lets look at this more mathematically:

1050 + 5a = 1550 + 5b
(Here a is the constant additive rate by which org A is growing and likewise for B)

1550-1050 = 5(a-b)
(a-b)=500/5 ---- This is what you arrived at directly
a-b =100

Hope this helps!
Regards.
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Shouldnt this be A*(1+x)^5=B*(1+y)^5
they are saying constant rate of increase year on year. This is compounding right?
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Here there is a fault- the question explicitly states the number of member increases by a constant rate(not constant number) so there will a compounding of the number every year. if the question would have said by a constant number then we could use your method............

vmelgargalan
1050 + 5x = 1550 + 5y

5x - 5y = 500

(Divide both sides by 5)

x - y = 100

Only two digits were x - y = 100 is 130 and 30
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I also have the same doubt, when should we use AP or GP? I often get confused between two

Rogerper123
Why do we solve by means of an arithmetic progression and not a geometric prgression?

What I initially did was 1050*a^5 = 1550*b^5. a and b being A and B respective constant rates.
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there was a similar question of clark and talbot university refer that questions dicussion for a better explanation
Annukiran
Here there is a fault- the question explicitly states the number of member increases by a constant rate(not constant number) so there will a compounding of the number every year. if the question would have said by a constant number then we could use your method............

vmelgargalan
1050 + 5x = 1550 + 5y

5x - 5y = 500

(Divide both sides by 5)

x - y = 100

Only two digits were x - y = 100 is 130 and 30
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