Question

A rectangular field is 90m by 70m. A man walks round it at the rate of 4km per hour. What time will he take in making 5 rounds.

Answer 1

Answer: 24 Minutes

Explanation:

Given:

Length = 90m

Breadth = 70m

Rate of walking = 4km/hr

To find: In the given question, we have to find out the time taken by man for making 5 rounds.

Perimeter of rectangular field  = 2(length+breadth)

                                                  = 2(90+70)

                                                  = 2(160)

                                                  = 320

Therefore, Perimeter of rectangular field is 320m.

It is given that, Man walks at the rate of 4km/hr.

So, We have to convert it into km.

                           = 320/1000

                           = 0.320km

Time taken by person to walk 1 km = 4/60 (60 - Minutes)

Therefore, Distance travelled making

5 rounds = 5(0.320)

               = 1.6

Therefore, Distance travelled for making 5 rounds = 1.6 km.

We have to find time taken for making 5 rounds by person.

= 1.6 * 15 (Person needs 15 min for 1km)

= 24

Hence, Person takes 24 minutes for completing 5 rounds in rectangular field.

Answer 2

✬ Time = 0.4 hours or 24 minutes ✬

Step-by-step explanation:

Given:

• Length & Breadth of rectangular field is 90 m by 70 m respectively.
• A Man walked 5 rounds of this park.
• Speed of man is 4 km/h.

To Find:

• How much time man will take to complete 5 rounds ?

Solution: Distance covered by man in making one round of rectangular park will be the perimeter of the park.

As we know that

★ Perimeter of Rectangle = 2( Length + Breadth ) ★

$\implies{\rm }$ Perimeter = 2( 90 + 70 ) m

$\implies{\rm }$ Perimeter = 2 $\times$ 160

$\implies{\rm }$ Perimeter = 320 m

Thus distance covered by man in one round = 320 m

∴ Distance covered in making 5 rounds

➯ 5 $\times$ 320

➯ 1600 m or 1600/1000 = 1.6 km

Now, ★ Time = Distance/Speed ★

$\implies{\rm }$ Time = ( 1.6/4 ) hours

$\implies{\rm }$ Time = 0.4 hours

➼ Time taken in minutes = 0.4 $\times$ 60

➼ 24 Minutes

Hence, the man will take 0.4 hours or 24 minutes to make 5 rounds .