Question

Для ремонта квартиры купили 8 рулонов обоев длиной 10 м 50 см. После ремонта осталась одна четвёртая часть купленных обоев.Сколько метров обоев осталось? Реши задачу разными способами. Кто первый решит станет лучшим только если правильно!

Answer 1

10м50см×8=80м400см
80м400см=84м
84м:4=21м

Answer 2

Problem Analysis

To solve this problem, we need to determine how many meters of wallpaper are left after using 7/8 of the purchased rolls. We are given that 8 rolls of wallpaper were purchased, each with a length of 10 meters and 50 centimeters.

Solution 1: Using Fractions

One way to solve this problem is by using fractions. We know that 7/8 of the rolls were used, so the remaining fraction is 1/8. To find the length of the remaining wallpaper, we can multiply the length of one roll by the remaining fraction.

The length of one roll is 10 meters and 50 centimeters, which can be converted to meters as follows: 10 meters + 50 centimeters = 10 meters + 0.50 meters = 10.50 meters.

Now we can calculate the length of the remaining wallpaper: 1/8 * 10.50 meters = 1.3125 meters.

Therefore, 1.3125 meters of wallpaper are left.

Solution 2: Using Decimals

Another way to solve this problem is by converting the fractions to decimals. We know that 7/8 of the rolls were used, so the remaining fraction is 1/8. To find the length of the remaining wallpaper, we can multiply the length of one roll by the remaining fraction.

The length of one roll is 10 meters and 50 centimeters, which can be converted to meters as follows: 10 meters + 50 centimeters = 10 meters + 0.50 meters = 10.50 meters.

Now we can calculate the length of the remaining wallpaper: 1/8 * 10.50 meters = 1.3125 meters.

Therefore, 1.3125 meters of wallpaper are left.

Solution 3: Using Proportions

We can also solve this problem using proportions. We know that 7/8 of the rolls were used, so the remaining fraction is 1/8. To find the length of the remaining wallpaper, we can set up a proportion.

Let x represent the length of the remaining wallpaper. The proportion can be set up as follows: (7/8) / (10.50 meters) = (1/8) / x.

To solve for x, we can cross-multiply and solve the equation: (7/8) * x = (1/8) * 10.50 meters, 7x/8 = 1.3125 meters, 7x = 10.50 meters, x = 10.50 meters / 7, x = 1.50 meters.

Therefore, 1.50 meters of wallpaper are left.

Summary

There are multiple ways to solve this problem. Using fractions, we found that 1.3125 meters of wallpaper are left. Using decimals, we also found that 1.3125 meters of wallpaper are left. Using proportions, we found that 1.50 meters of wallpaper are left.