Question

Некто задумал число он увеличил его на 10 полученый результат уменьшил в 2 раза полученое число уменьшил на 10 полученый результат увеличил в 2 раза в результате всех вычеслений получилось число 90 какое число он задумал

Answer 1

90*2=180, 180-10=170 
ответ 170

Answer 2

Задуманное число = х
Теперь все действия:
[((х + 10) : 2)) - 10] * 2 = 90
[((x + 10) : 2)) - 10] = 90 : 2
(x + 10) : 2 - 10 = 45
(x + 10) : 2 = 45 + 10
x +10 = 55 * 2
x + 10 = 110
x = 110 - 10
x = 100
Ответ: 100 - задуманное число.
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Проверка:
((100 + 10) : 2  - 10)) * 2 = 90
(110 : 2 - 10) * 2 = 90
45 * 2 = 90
90 = 90

Answer 3

Problem Analysis

To solve this problem, we need to determine the number that was initially thought of by following the given steps: 1. The number is increased by 10. 2. The resulting number is then reduced by half. 3. The new number is reduced by 10. 4. Finally, the resulting number is doubled.

Let's solve this step by step.

Step 1: Increase the Number by 10

The initial number is increased by 10.

Step 2: Reduce the Result by Half

The resulting number from step 1 is reduced by half.

Step 3: Reduce the New Number by 10

The new number from step 2 is reduced by 10.

Step 4: Double the Resulting Number

The resulting number from step 3 is doubled.

Final Result

After performing all the calculations, the resulting number is 90.

Solution

To find the initial number, we need to reverse the steps. Let's go through each step in reverse order.

Step 4: Double the Resulting Number

To reverse the doubling operation, we need to divide the resulting number by 2.

Step 3: Increase the New Number by 10

To reverse the reduction by 10, we need to add 10 to the new number.

Step 2: Double the Result and Reduce by Half

To reverse the reduction by half, we need to double the result.

Step 1: Decrease the Number by 10

To reverse the increase by 10, we need to subtract 10 from the number.

By reversing the steps, we can find the initial number.

Reversing the Steps

1. The resulting number is 90. 2. Double the resulting number: 90 * 2 = 180. 3. Increase the new number by 10: 180 + 10 = 190. 4. Divide the result by 2: 190 / 2 = 95. 5. Decrease the number by 10: 95 - 10 = 85.

Therefore, the initial number that was thought of is 85.

Please let me know if I can help you with anything else.