Question

Двигаясь по течению реки, расстояние в 48 км теплоход проходит за 3 часа, а плот за 24 часа. Какова скорость теплохода при движении по озеру.

Answer 1

В озере вода не движется, скорость течения ноль. Требуется найти скорость течения реки. 48 км /24 часа = 2 км/час (из скорости плота и расстояния). 
Решение
48 : 3 = 16 км / ч - скорость теплохода по течению
48 : 24 = 2 км / ч - скорость плота по течению, т.е. скорость течения
16 - 2 = 14 км / ч - скорость теплохода в стоячей воде, т.е. скорость при движении по озеру.
НУ ИЛИ ТАК
если скорость теплохода х, то по реке он движется со скоростью х+2
(х+2)*3=48
х+2=16
скорость 14 км в час
Удачи!

Answer 2

Calculation of the Speed of the Boat

To calculate the speed of the boat when moving on the lake, we need to determine the speed of the current. We can use the information provided about the distances and times taken by the boat and the raft to calculate the speed of the current.

Let's denote the speed of the boat as v and the speed of the current as c.

According to the information given, the boat covers a distance of 48 km in 3 hours when moving downstream with the current. This means that the effective speed of the boat is the sum of its own speed and the speed of the current, resulting in a total speed of v + c.

Similarly, the raft covers the same distance of 48 km in 24 hours when moving downstream with the current. Therefore, the effective speed of the raft is c.

Using the formula distance = speed × time, we can set up the following equations:

1. For the boat: 48 = (v + c) × 3. 2. For the raft: 48 = c × 24.

Let's solve these equations to find the values of v and c.

From equation 2, we can express c in terms of v:

c = 48 / 24 = 2 km/h.

Substituting this value of c into equation 1:

48 = (v + 2) × 3.

Simplifying the equation:

48 = 3v + 6.

3v = 48 - 6.

3v = 42.

v = 42 / 3 = 14 km/h.

Therefore, the speed of the boat when moving on the lake is 14 km/h.

Answer:

The speed of the boat when moving on the lake is 14 km/h.