Answer:
the second bag
Step-by-step explanation:
to find it u have to think of it as fractions. 3/20 has to equal ?/500 so divide 500 by 20 and you get 25. then multiply the 3 by 25 which equals 75. so it would be 75/500 which is less than 170/500
Well, let's say the numbers are "a" and "b"
so a * b = ab
ok... now, if we reduce "a" by 25%, that means the new size is just 75% of the old one, how much is 75% of a? well, (75/100) * a, or 0.75a
now let's reduce "b" by 50%, that means the new size is 50% or half, how much is 50% of b? well (50/100)*b, or 0.5b

now, the new size of "ab" is just 0.375ab... well, let's revert the decimal format by simply multiplying by 100
0.375 * 100, is 37.5%
the new size of "ab" is just 37.5% of the original "ab"
it decreased by 100 - 37.5 or 62.5%
What are u asking, the difference?