Question

A student uses a solution that contains 16 grams of water to conduct an evaporation experiment. ​​At the end of one hour, the amount of water in the solution has decreased by 3.5%. ​At the end of two hours, the amount of water in the solution has decreased by another 4.25%. ​Which calculations can be used to determine the amount of water, in grams, remaining in the solution at the end of the second hour?

Answer 1

Good evening

Answer:

14.7838 grams

Step-by-step explanation:

Rule : _____________________________________________________

decrease something by p% then decrease by q% means multiply by

$(1-\frac{p}{100})(1-\frac{q}{100})$

__________________________________________________________

Note : in our case the amount of water in the solution has decreased by 3.5% then by 4.25% consecutively____________________________________

Let’s apply what we have learnt:

the amount of water remaining in the solution at the end of the second hour is

$16(1-\frac{3.5}{100})(1-\frac{4.25}{100})=14.7838$

Hope this helps.

Answer 2

Answer:

3.5% decrease means 96.5% remaining

0.965(16)

4.25% decrease means 95.75% remaining

0.9575(0.965(16))

= 14.7838 grams