Question

В гонках по экскалатору участвовали слон, тигр и мартышка. Мартышка шла вниз по движущемуся экскалатору и на спуск потратила 1 минуту. Тигр спускался по движущемуся вниз экскалатору в 2 раза быстрее мартышки и потратил на это 45 секунд. А слон стоял неподвижно на движущемся экскалаторе. За сколько секунд Слон спустился по экскалатору? Варианты ответов: 75, 85, 90, 100

Answer 1

75 секунд.Потому что благодаря своему ходу мартышка добралась до точки Б на 15 секунд быстрее,а тигр на 30 секунд.Следовательно эскалатор проходит этот путь за 75 секунд.

Answer 2

Problem Analysis

In this problem, we are given that a monkey took 1 minute to go down a moving escalator, a tiger went down the moving escalator twice as fast as the monkey and took 45 seconds, and an elephant stood still on the moving escalator. We need to determine how many seconds it took for the elephant to go down the escalator.

Solution

Let's assume the speed of the monkey is M and the speed of the tiger is 2M. Since the monkey took 1 minute (60 seconds) to go down the escalator, we can set up the equation:

Distance = Speed x Time

For the monkey: Distance = M x 60

For the tiger: Distance = 2M x 45

Since the distance covered by the monkey and the tiger is the same, we can equate the two equations:

M x 60 = 2M x 45

Simplifying the equation, we get:

60 = 2 x 45

60 = 90

This equation is not true, which means our assumption that the distance covered by the monkey and the tiger is the same is incorrect. Therefore, we need to adjust our assumption.

Let's assume the speed of the escalator is E. Since the monkey took 1 minute (60 seconds) to go down the escalator, the distance covered by the monkey is equal to the speed of the escalator:

Distance = E x 60

For the tiger, who went down the escalator twice as fast as the monkey, the distance covered is:

Distance = (E + 2M) x 45

Since the distance covered by the monkey and the tiger is the same, we can equate the two equations:

E x 60 = (E + 2M) x 45

Simplifying the equation, we get:

60E = 45E + 90M

15E = 90M

Dividing both sides of the equation by 15, we get:

E = 6M

Now, let's consider the elephant. The elephant stood still on the escalator, so the distance covered by the elephant is equal to the speed of the escalator:

Distance = E x Time

Since we know that E = 6M, the equation becomes:

Distance = 6M x Time

We need to find the time it took for the elephant to go down the escalator, so we can rearrange the equation to solve for Time:

Time = Distance / (6M)

Substituting the value of Distance as E (the speed of the escalator) and Time as 60 seconds (1 minute), we get:

60 = E / (6M)

Simplifying the equation, we get:

60 = E / (6M)

60 = (6M) / (6M)

60 = 1

This equation is not true, which means our assumption that the distance covered by the monkey and the tiger is the same as the distance covered by the elephant is incorrect. Therefore, we need to adjust our assumption.

Since the elephant stood still on the escalator, the distance covered by the elephant is equal to 0. Therefore, the time it took for the elephant to go down the escalator is also 0 seconds.

Answer

The elephant took 0 seconds to go down the escalator.

Explanation

The monkey took 1 minute (60 seconds) to go down the escalator, the tiger took 45 seconds, and the elephant stood still on the escalator. Since the elephant did not move, it did not cover any distance and therefore did not take any time to go down the escalator.