Problem Solving

Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?

A) 2
B) 50
C) 92
D) 96
E) 98

Which method will you apply?

Rahul@gurome wrote:

beat_gmat_09 wrote:Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?

A) 2
B) 50
C) 92
D) 96
E) 98

Which method will you apply?

Observe that before and after evaporation the materials other than water remains same.

Before evaporation:
Weight of other material = 1% of 100 pounds = 1 pound

After evaporation:
Other material = 2% by weight
Now 2% weighs 1 pound => 100% weighs 50 pounds.

The correct answer is B.

Thanks Rahul. Can you please explain how to setup a equation ?

NICE quistion

Hi Rahul,

Thanks for the explanation.But i have a doubt

Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?


"Observe that before and after evaporation the materials other than water remains same".Could you please explain how did you come to this conclusion.

Cucumbers weigh 100 pounds --> 99% water
Cucumbers weigh ? pounds -->98% waterd

Can we think that the other material weight can still be 1% and water % as 98%.

Please correct me.

Regards,
Andy.

Yeah Rahul..U are right..
Anyways sorry for the late reply, Took a break.

Starting:
total wt.: 100lb
Water 99% = 99lb
Other 1% = 1lb

End state
total wt = X
water 98% = 90X/100
Other 2% = X*2/100 = 1lb (from above)
==> X = 50

beat_gmat_09 wrote:Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?

A) 2
B) 50
C) 92
D) 96
E) 98

Which method will you apply?

At the start:
1 pound cucumber, 99 pounds water

After the evaporation:
1 pound cucumber = 2% of the total weight

Now look at the answer choices. Only answer choice B works:
.02*50 = 1.

The correct answer is B.

The equation would look like this:
1 pound cucumber = 2% of the total weight
1 = .02x
x = 1/.02 = 100/2 = 50.

You can also look at it this way:

x is the weight of the cucumber after water evaporation, i.e. with 98% water

x - 98% of x = 1 pound

x - 0.98x = 1

0.02x = 1

x = 1/0.02

x = 50

Answer is B

total weight of water = 99 pounds
total weight of cucumber san water = 1 pound

After evoparation
let say total weight is x

So 2*x/100 = 1 => x = 50

My answer:

X is the weight of water that was evaporated

Before evaporation: 100 pounds of cucumbers ---- 99 pounds of water

After evaporation : 100-X pounds of cucumbers ---- 99-X pounds of water

So

(99-X)/(100-X)=0.98 <=> 1=0.02X => X=50 => new weight of cucumbers = 100 - 50 = 50

Confused on how the question was answer

beat_gmat_09 wrote:Each of the cucumbers in 100 pounds of cucumbers is composed of 99% water, by weight. After some of the water evaporates, the cucumbers are now 98% water by weight. What is the new weight of the cucumbers, in pounds?

A) 2
B) 50
C) 92
D) 96
E) 98

Which method will you apply?

99% water in 100 pounds means ==> 1 pound solid cucumber + 99 pound water
After evaporation, 1 pound solid cucumber remains intact and only water gets evaporated

S0 1 + 0.98x = x (water now forms 98% of total weight)
hence 0.02x = 1.. so x= 50 pounds

Very good question:

0.02 x z = 1

Therefore z = 1/0.02 = 50.