gmat009 wrote:Before a certain tire is used, 40 percent of its total weight consists of tread. If during a lifetime of use, 50 percent, by weight, of the tire’s tread is lost and no other parts of the tire is lost, what per cent of the tire’s total remaining weight consists of the remaining tread?
A. 55%
B. 20%
C. 25%
D. 30%
E. 35%

Let the weight of the tire = 10kgs

40% of 10 = 4

Tire lost 50% of its weight

10 - 5 = 5

out of 5kgs only 1kgs of tread is left, because we have lost 4 kgs with the 50% weight.


1/5*100 = 20%

Morgoth would the answer be 25

Lets say 100 is the initail weight

40% = 40 is the tread
60% = 60 non tread

50% of weight of tread is lost

50% of 40 i.e. 20

Remaining tread = 20
Total remaining weight is 80 (since 20 tread is gone)

So 20/80*100 = 25 %

Thoughts??

Answer is indeed 25.

Just missed it. I misinterpreted the tire's tread part. I thought entire tire lost 50% of its weight

Thanks.

All the best.

My thought as well !
Ans=25%

Assume the total weight of the tire =100

and 40% is thread= the weight is 40

and life time use ! 50% is lost -- so the weight is reduced to 20

now the total weight is 80 and thread weight is 20

20 is wat percent of 80 =25% is the OA

" no other parts of the tire is lost " - I know this is not a verbal question, but the way this questions is formulated - it makes you wonder how credible the source is.
Statement above should have been: " no other parts of the tire are/were lost "

Getting to the question I agree with Cramya's solution - the answer indeed is 25%