Question

Гарри Поттер идет от Хогвартса до Хогсмита 30 минут, а Гермиона Грейнджер – 40 минут. Через сколько минут Гарри догонит Гермиону, если она вышла на пять минут раньше него? Варианты а)20 б)15 в)5

Answer 1

Скорость Гарри
1) V1 = 1/30 * S
Скорость Гермионы
2) V2 = 1/40*S
Догоняет из-за разности скоростей
3) Vп  = V1 - V2 = (1/30 - 1/40)*S = 1/120 *S
Время погони Гарри
4) T = S/Vп = S : (S/120) =  1/120 ч = 5 мин - ОТВЕТ

Answer 2

Problem Analysis

We are given that Harry Potter takes 30 minutes to walk from Hogwarts to Hogsmeade, while Hermione Granger takes 40 minutes. We need to determine how many minutes it will take for Harry to catch up to Hermione if she leaves 5 minutes earlier.

Solution

To solve this problem, we can set up an equation based on the given information. Let's assume that Harry catches up to Hermione after x minutes.

Since Hermione leaves 5 minutes earlier, she would have already been walking for x + 5 minutes when Harry catches up to her.

During this time, Harry would have been walking for x minutes.

Since Harry walks at a faster pace, we can set up the following equation:

x + 5 = 30 - x

Simplifying the equation, we get:

2x = 25

Solving for x, we find:

x = 12.5

Therefore, Harry will catch up to Hermione after 12.5 minutes.

Answer

Harry will catch up to Hermione after 12.5 minutes.