Question

На день рождения дедушка получил самый дорогой подарок. У него родилась внучка. Через несколько лет оказалось, что дедушке столько лет, сколькомесяцев внучке. Дедушке с внучкой вместе 78 лет. Найди возраст дедушки ивнучки в годах.​

Answer 1

Ответ:

Дедушке 72г

Внучке 6л

Пошаговое объяснение:

Из рассказа делаем систему уравнений и решаем. Их сумма лет равен 72. Возраст дедушки равен возрасту внучки в месяцах.

$\left \{ {{a+b=78} \atop {a=12b}} \right.$  

a=78-b

78-b=12b

13b=78

b=6

a=78-6=72

Answer 2

Problem Analysis

To find the ages of the grandfather and granddaughter, we need to solve a system of equations based on the given information. We know that the sum of their ages is 78 years, and the grandfather's age is equal to the granddaughter's age in months. Let's denote the grandfather's age in years as G and the granddaughter's age in years as D. We can set up the following equations:

Equation 1: G + D = 78 (sum of their ages is 78 years) Equation 2: G = 12D (grandfather's age is equal to the granddaughter's age in months)

We can solve this system of equations to find the values of G and D.

Solution

To solve the system of equations, we can substitute Equation 2 into Equation 1:

12D + D = 78 13D = 78 D = 78 / 13 D = 6

Now that we have the value of D, we can substitute it back into Equation 2 to find G:

G = 12D G = 12 * 6 G = 72

Therefore, the grandfather is 72 years old and the granddaughter is 6 years old.

Answer

The grandfather is 72 years old and the granddaughter is 6 years old.