Question

30 страниц одна машинистка печатает на 1.5 часа быстрее,чем вторая.За сколько времени вторая машинистка напечатает 60 страниц,если,работая вместе,они печатают 30страниц за 1 час?

Answer 1

Х - 1,5 часа печатает 30стр одна 1-ая машинистка
30 : х стр в час скорость печатания 2-ой машинистки
30 : ( х - 1,5) стр в час скорость печатания 1-ой машинистки
вместе они печатают 30 страниц за 1 час поэтому
30 : х +30 : ( х - 1,5) =30 или
1/х + 1 / ( х - 1,5) =1
( х - 1,5) +х = х* ( х - 1,5) 
х2 -3,5х +1,5 =0 или 2х2 -7х +3 =0
Решая это квадратное уравнение найдём
х=3 ( корень х= 1/2 не удовлетворяет условию задачи)
Ответ за 3 часа

Answer 2

Problem Analysis

To solve this problem, we need to determine the time it takes for the second typist to print 60 pages, given that they work together to print 30 pages in 1 hour and the first typist is 1.5 hours faster than the second typist.

Solution

Let's denote: - T1: Time taken by the first typist to print 30 pages - T2: Time taken by the second typist to print 30 pages - T: Time taken by the second typist to print 60 pages

Given that the first typist is 1.5 hours faster than the second typist, we can express T1 in terms of T2 as: T1 = T2 - 1.5

We also know that when working together, they print 30 pages in 1 hour, so their combined rate is: 1 / T1 + 1 / T2 = 1 / 1

We can use the combined rate to find the individual rates of the first and second typists, and then use these rates to find the time it takes for the second typist to print 60 pages.

Calculation

Let's solve for T2 using the combined rate: 1 / (T2 - 1.5) + 1 / T2 = 1

Solving this equation will give us the value of T2, and then we can find T using the relationship between T1 and T2.

Result

The time it takes for the second typist to print 60 pages can be calculated using the above approach.