There are two tanks A, B. After 100 litres of water

Question

There are two tanks A, B. After 100 litres of water got drained from tank A and moved to to tank B, the volume of water in tank B increased by 20 percent. What was the original volume of water in tank A?

1) Before the 100 litres were drained and moved, the sum of the volume of water in the two tanks was 900 litres.
2) After the 100 litres were drained and moved, the volume of water left in tank A was half the volume of water in tank B.

SonalSinha803 · Accepted Answer

Let, volume of water in tank A and B be V_a and V_b respectively. Given : 100 = (20/100)* V_b

Thus, V_b = 500 litres

Statement 1 : V_a + V_b = 900
Also, V_b = 500. Thus, V_a = 400.

Sufficient.

Statement 2 : After V_b = 500 + 100 = 600

V_a' = (1/2) V_b' = (1/2)* 600 = 300

V_a' = 300 + 100 = 400

Sufficient.

Thus, both statements are alone sufficient to answer the question.

I go with D.

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EgmatQuantExpert · Answer

SOLUTION

We are given: 
 • After  100  litres of water is moved from tank A to tank B, the volume of water in tank B is increased by  20  percent.

Let us assume:
 • The volume of water in tank A= x litres 
• The Volume of water in tank B =y litres.

Thus, 
 •  \frac{20}{100}  *y = 100 
•  y=500

We need to find: 
 • What is the value of  x ?

Statement-1 : “ Before the  100  litres were drained and moved, the sum of the volume of water in the two tanks was  900 litres ”.

•  x + y= 900 
•  x = 400  litres

Thus,  statement 1 alone is sufficient to answer the question .

Statement-2 : “ After the  100 litres were drained and moved, the volume of water left in tank A was half the volume of water in tank B ”.
 •  x-100 =  \frac{1}{2} * (y+100)
•  2x-200 =  500+100 
•  2x=800 
•  x=400

Thus,  statement 2 alone is sufficient to answer the question .

We can find the answer by each of the statement alone. 
 Answer: D

stne · Answer

Dear Moderator,
Kindly retag this question to " Arithmetic " rather than " Work /rate problems". Thank you.

Bunuel · Answer

_______________
Fixed. Thank you.

hotshot02 · Answer

From the statement - Vol. of B is 500 litres (since 20% increase is 100 litres)
statement A - sum is 900 litres so 900-500 = 400 litres is the capacity of tank A.
statement B - after moving 100 litres, water left in tank A is 1/2 of tank B i.e. 500/2 = 250

both statements alone are sufficient. hence D

saukrit · Answer

100 litres of water drained from Tank A is 20% of initial volume of Tank B. Which means 20% of B's original water volume= 100 litres. Hence original volume of Tank B is known i.e. 500 litres(100*5)

1) Before the 100 litres were drained and moved, the sum of the volume of water in the two tanks was 900 litres. 
Using this we can find the original volume of water in tank A as we already know the original volume of Tank B and from this statement we also know that total sum of both the tanks volume is 900. Hence this is  Sufficient

2) After the 100 litres were drained and moved, the volume of water left in tank A was half the volume of water in tank B. 
Using this statement also we can find the original volume in A, as A-100=1/2(B+100). Hence this statement is also  Sufficient

Hence , the answer in D

pulak1988 · Answer

This is very simple. No need to calculate. 
solving the question into equation gives A= 6B/5 + 100. so we need B for A's value.

stmnt 1: gives an equation. solving it gives B.
stmnt 2: same..

hence, D

bumpbot · Answer

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There are two tanks A, B. After 100 litres of water

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