In a farm, the ratio of pigs to chickens is 13 to 28. When

Question

In a farm, the ratio of pigs to chickens is 13 to 28. When 15 pigs were added to the farm, the ratio of pigs to chickens became 4 to 7. What was the original total number of pigs and chickens in the farm?

(A) 200
(B) 205
(C) 210
(D) 215
(E) 220

I suppose that,    + 15 pigs can be    to reduce the fraction we probably will receive   ,
so 3 in numrator is equal - 15 pigs
the total number of pigs before new comers = 13*5=75

how can I get the number of chickens?

Thanx

KarishmaB · Accepted Answer

Pigs:Chicken = 13:28
No of pigs = 13x, No of chicken = 28x

When 15 more pigs were added, ratio becomes 4:7 i.e.

\frac{(13x+15)}{28x} = \frac{4}{7} 
x = 5

Initially, the no of pigs was 13x = 13*5 = 65
No of chicken was 28x = 28*5 = 140
Original total = 205

or Original total = 13x + 28x = 41x = 41*5 = 205

Bunuel · Answer

Similar questions to practice; two-numbers-are-in-the-ratio-5-6-if-22-is-added-to-the-135168.html a-physics-class-has-majors-and-non-majors-in-a-ratio-of-4-to-133685.html the-ratio-of-two-positive-numbers-is-3-to-4-if-k-is-added-95198.html Hope it helps.

actleader · Answer

VeritasPrepKarishma, Bunuel
thanx for solving the problem but I'd like yo know how can I found the number of chickens when I deducted that 3 in numerator is equal - 15 pigs?

KarishmaB · Answer

Yes, when you say that the the additional 3 is actually 15, you get 5 as the multiplier.

In your solution above, you wrote:
"the total number of pigs before new comers = 13*5=75" which should actually be "the total number of pigs before new comers = 13*5=65" (calculation error)

Next, no of chickens will be 28*5 = 140
(after all, you have already found that the multiplier of the ratio is 5. You multiplied 13 by 5 to get the number of pigs. You multiply 28 by 5 to get the number of chickens)

Vips0000 · Answer

15sec approach to solve this question:
Original ratio is 13:28, which shows the original total must be a multiple of 41. Only 205 among answer choices is multiple of 41.
Ans B it is.

Further, since you are interested in finding number of chickens too..Once you've total number, you can deduce number of chickens, pigs and everything else since you've the ratio given.

CEdward · Answer

P:C = 13x:28x

13x + 15 / 28x = 4/7
x = 5

13(5) = 65
28(5) = 140

65 + 140 = 205

Answer is B.

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

In a farm, the ratio of pigs to chickens is 13 to 28. When

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions

In a farm, the ratio of pigs to chickens is 13 to 28. When

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards