Question

aboat can cover 3km upstream in 12min if the speed of the streem is 1.5kmph how much distance can the boat cover downstream in 3 hrs​

Answer 1

Answer:

49.5 km

Step-by-step explanation:

There are 15 12 minutes in 3 hours so if 12 minutes is equivalent to 3 km then simplified is 3 multiplied by 15 which is 45 km.

If the stream goes on for 3 hours then  1.5 is multiplied by 3 which is 4.5km because there are 3  1 hours in 3 hours.

Then if you add up 45 km and 4.5 km you get 49.5 km

Answer 2

Given Question :-.

A boat can cover 3 km upstream in 12 min. If the speed of the stream is 1.5 kmph, how much distance can the boat cover downstream in 3 hrs.

Solution :-

Speed of the stream = 1.5 km per hour

Let speed of the boat = 'x' km per hour

So,

• Speed of upstream = x - 1.5 km per hour

• Speed of downstream = x + 1.5 km per hour

Now,

According to statement,

• Distance covered in upstream = 3 km

• Time taken = 12 minutes = 12/60 = 1/5 = 0.2 hours

• Speed of upstream = x - 1.5 km per hour

We know,

• Distance = Speed × Time

$\rm :\longmapsto\:3 = 0.2(x - 1.5)$

$\rm :\longmapsto\:3 = \dfrac{2}{10} (x - 1.5)$

$\rm :\longmapsto\:30 = 2x - 3$

$\rm :\longmapsto\:2x = 33$

$\rm :\implies\:x = 16.5 \: km \: per \: hour$

Now,

In downstream,

• Speed of downstream = x + 1.5 = 16.5 + 1.5 = 18 km/hour

• Time = 3 hours

So,

• Distance covered = 18 × 3 = 54 km.

Basic Concept Used :-

Writing System of Equation from Word Problem

1. Understand the problem.

• Understand all the words used in stating the problem.

• Understand what you are asked to find.

2. Translate the problem to an equation.

• Assign a variable (or variables) to represent the unknown.

• Clearly state what the variable represents.

3. Carry out the plan and solve the problem.