Final answer:
To find Hamid's weight a month ago, the equation 88kg = 1.10 × w is used, which is derived from the fact that his current weight is 10% more than his previous weight. After solving for w, it is found that Hamid weighed 80kg a month ago.
Step-by-step explanation:
The subject of the question is to find out how much Hamid weighed a month ago if he currently weighs 88kg after gaining 10% in weight. To do this, we need to calculate the percent change in weight.
Let's denote Hamid's previous weight as w. According to the problem, his current weight is 10% more than his previous weight, which means:
88kg = w + (10/100) × w
This can be simplified to:
88kg = 1.10 × w
To find w, we solve for w by dividing both sides of the equation by 1.10:
w = 88kg / 1.10
Now we do the calculation:
w = 80kg
So, Hamid weighed 80kg a month ago.