Explain why a change from 20 to 40 is a 100% increase, but a change from 40 to 20 is a 50% decrease.
increasing 20 to 40 is the same as increasing 20 by c. so, it is a 100% increase. decreasing 40 to 20 is the same as decreasing 40 by one-half of c. so, it is a 50% decrease.
i don't understand how to fill in the blanks.

I believe the answer you are looking for is:

Increasing 20 to 40 is the same as increasing 20 by 20 (or itself), so it is a 100% increase. Decreasing 40 to 20 is the same as decreasing 40 by 1/2 or by 20. So it is a 50% increase.

Basically, when going from 20 to 40, the number is being doubled, and when youre going from 40 to 20 you are cutting the number in half.

neither i nor ii 56 / 4.9 = 11.91489362 and 82 / (11+5) =5.125 so i is wrong

ii. (24/8+2) times 3 = 15 and (42+9)/2 =25.5

step-by-step explanation:

56

4 candies

step-by-step explanation:

7 x 28 = 196

200 - 196 = 4 candies remaining.