Decrease the number by 50%, then increase by 80%. How much will it turn out?

1. Let’s denote the initial number by the letter A. If we decrease it by 50%, then it becomes equal in percentage terms:

100 – 50 = 50%.

2. Now let’s find how much remains of the number after decreasing it by that much:

100% – A;

50% – H.

Where from:

X = A x 50/100;

X = 0.5 x A.

3. If the number increases by 80%, then it becomes equal in percentage terms:

100 + 80 = 180%.

4. Now 100% of the number is 0.5 x A, and how much is 180%, we will solve using the method of proportions:

100% – 0.5 x A;

180% – W.

Where from:

Y = 0.5 x A x 180/100;

Y = 0.9 x A.

Answer: if you do the above procedures with the number, it will become equal to 0.9 x A.