Question

Внучке столько же месяцев, сколько лет дедушке. Дедушке с внечкой 78 лет Бабушка на три года младше дедушки. Сколько лет бабушке?

Answer 1

Пусть внучке х месяцев, тогда ей х/12 лет
пусть дедушке у лет, тогда составляем х = у
х/12 + у = 78 подставляем
х/12 + х = 78
13х/12 = 78
13х = 78 на 12
х=72 значит внучке 6 лет
дедушке 72 года а бабушке 72 - 3 = 69 лет

Answer 2

Problem Analysis

To solve this problem, we need to determine the age of the grandmother based on the given information. We know that the granddaughter is the same number of months old as the grandfather is in years. The grandfather is 78 years old, and the grandmother is three years younger than the grandfather.

Solution

Let's break down the problem step by step:

1. We know that the granddaughter is the same number of months old as the grandfather is in years. Since the grandfather is 78 years old, the granddaughter is also 78 months old. 2. We know that the grandmother is three years younger than the grandfather. So, to find the age of the grandmother, we subtract 3 years from the grandfather's age.

- 78 years (grandfather's age) - 3 years = 75 years (grandmother's age) Therefore, the grandmother is 75 years old.

Answer

The grandmother is 75 years old.