Question

Задача:Турист наметил пройти маршрут длинной 90км. В первый день он прошел x км, во второй день - в 2 раза больше, чем в первый день, а в третий день - на 5км меньше, чем во второй. Какую часть пути прошел турист за эти три дня.

Answer 1

х+2х+2х-5=90

5х-5=90

5х=90+5

5х=95

х=95:5

х=19 прошёл в 1 день

19*2=38 во 2-ой день

38-5=33 в 3 день

90-(19+38+33)=0 прошёл 100%

Answer 2

Problem Analysis

A tourist plans to walk a route that is 90 km long. On the first day, the tourist walks x km. On the second day, the tourist walks twice as much as on the first day. On the third day, the tourist walks 5 km less than on the second day. We need to determine what fraction of the route the tourist has walked in these three days.

Solution

To find the fraction of the route the tourist has walked, we need to calculate the total distance walked by the tourist in these three days and divide it by the total distance of the route.

Let's calculate the distance walked on each day:

- On the first day: x km - On the second day: 2x km (twice as much as the first day) - On the third day: (2x - 5) km (5 km less than the second day)

To find the total distance walked, we add up the distances walked on each day:

Total distance walked = x + 2x + (2x - 5)

Simplifying the expression:

Total distance walked = 5x - 5

Now, we can calculate the fraction of the route the tourist has walked by dividing the total distance walked by the total distance of the route:

Fraction of the route walked = (Total distance walked) / (Total route distance)

Fraction of the route walked = (5x - 5) / 90

Therefore, the tourist has walked (5x - 5) / 90 of the route in these three days.

Example Calculation

Let's say the tourist walked 10 km on the first day (x = 10). We can substitute this value into the formula to find the fraction of the route walked:

Fraction of the route walked = (5 * 10 - 5) / 90

Fraction of the route walked = 45 / 90

Fraction of the route walked = 0.5

Therefore, if the tourist walked 10 km on the first day, they would have walked half of the route in these three days.

Answer

The fraction of the route the tourist has walked in these three days is (5x - 5) / 90. The specific value of the fraction depends on the distance walked on the first day (x).