A student mixes 15 milliliters of 20% hydrochloric acid solution, 5 milliliters of 75% hydrochloric acid, and 20 milliliters of 40% hydrochloric acid solution. What percent is the final mixture –
give your answer to the nearest percent?

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

What do you need with it’s not a question your just stating what it says