Price Change

Sometimes, a question on the test will ask you to calculate a new price—usually after something goes up or down. This type of question is actually quite simple, and chances are, you’ve already done it many times in real life without even thinking about it.

Let’s take a real-life example. On Monday, you buy 30 liters of gas. A few days later, you read that the price of gas has gone up by $0.05 per liter. Now you wonder, how much more would you pay for the same 30 liters?

Here’s how to figure it out. You take 30 × 0.05, because the price went up 5 cents for each liter. $0.05 × 30 = $1.50
That’s it. The total increase is $1.50. If you were to buy gas today, it would cost $1.50 more than it did on Monday.

Now let’s look at a different situation.
A grocery store sells apples for $2 per kilogram. They raise the price by $0.50 per kilogram. You want to buy 2 kilograms of apples.
First, find the new price per kilogram: $2 + $0.50 = $2.50.
Now multiply that by how many kilograms you want to buy: $2.50 × 2 = $5.00
So, you’ll pay $5.00 in total for 2 kilograms of apples at the new price.

Now let’s try one more example, just a little more challenging. A family rents a small boat for 3 hours. The rental rate used to be $18 per hour, but now it has increased by $2.50 per hour.
Step 1: Add the price increase to the original hourly rate: $18 + $2.50 = $20.50
Step 2: Multiply by the number of hours: $20.50 × 3 = $61.50
So the family will now pay $61.50< to rent the boat for 3 hours at the new price. All of these problems use the same idea: when a price changes, multiply the new amount by how much you’re buying or using. Whether it’s liters, hours, or kilograms—the method stays the same. And it’s a method you can trust to get the right answer on test day.[/spoiler] [spoiler title=" Summary in Flashcards" style="fancy" icon="arrow"] Click anywhere on the flashcard to see the answer. To move to the next question, click on the small arrow at the bottom.[flashcard_set id='342825'] [/spoiler]