Question

За 8 одинаковых по цене карандашей Ира заплатила 16 рублей . какова стоимость четырёх таких карандашей?реши задачу двумя способами.

Answer 1

16:8=2(р)-за 1 карандаш
2*4=8(р)-за 4 карандашей

Answer 2

16:8=2(р) стоит 1 карандаш
2*4=8(р) стоят 4 карандаша
  Ответ:4 рубля.

Answer 3

Problem Statement

Ира купила 8 одинаковых по цене карандашей и заплатила 16 рублей. Нужно определить стоимость четырех таких карандашей.

Solution 1: Using Proportions

Let's solve the problem using proportions. We know that the cost of 8 pencils is 16 rubles. We can set up a proportion to find the cost of 4 pencils.

Let x be the cost of 4 pencils.

The proportion can be set up as:

8 pencils / 16 rubles = 4 pencils / x rubles

To solve for x, we can cross-multiply and solve the resulting equation:

8 * x = 16 * 4

Simplifying the equation:

8x = 64

Dividing both sides by 8:

x = 8

Therefore, the cost of four such pencils is 8 rubles.

Solution 2: Using Division

Another way to solve the problem is by dividing the total cost by the number of pencils.

We know that the cost of 8 pencils is 16 rubles. To find the cost of 4 pencils, we can divide the total cost by the number of pencils:

16 rubles / 8 pencils = 2 rubles per pencil

Since we want to find the cost of 4 pencils, we can multiply the cost per pencil by the number of pencils:

2 rubles per pencil * 4 pencils = 8 rubles

Therefore, the cost of four such pencils is 8 rubles.

Conclusion

Both methods yield the same result. The cost of four such pencils is 8 rubles.