# For Geeks & Brainiacs #05- Wet Sponge -

You have a wet sponge that weighs 200 grams which is 99% water by weight. If you squeeze some of the
water out of the sponge such that it is now only 98% water by weight, what would the wet sponge now
weigh?

**HINT**: You must first calculate how much the dry sponge weighs.

**ANSWER**:

*100 grams.*
**EXPLANATION**: At first, 1% of the total weight is the sponge itself (since 99% of the weight is
water). Therefore, the sponge weighs 2 grams when dry (1% × 200 grams). After squeezing some of the water
out, 2% of the total weight is the sponge itself (since 98% of the weight is water). If we let

**x** represent the total weight of the sponge, then: (2/100)

**x** = 2 grams
and therefore

**x** =

**100 grams**.

Do you have a

suggestion for this puzzle (e.g. something that should
be mentioned/clarified in the question or solution, bug, typo, etc.)?