contestada

On Monday, Nalim made a journey.
On Tuesday, she made the same journey.
Her average speed on Tuesday was 25% greater than her average speed on Monday.

Calculate the percentage reduction in the time her journey took on Tuesday compared with Monday.

Respuesta :

nada2135

Answer:

Step-by-step explanation:

Let's put in some numbers to make this easier to understand.

Let's say she has to travel 20 km.

On Monday, she travels at 4 kph.  This takes 5 hours.

On Tuesday she travels 25% faster, at 5 kph.  This takes 4 hours.  

To figure percent reduction we take

100 % * (old - new) / old  

100 % * (5 hr - 4 hr ) / 5 hr

100 % * 1 hr / 5 hr

100 % * 0.20

20% reduction.

MrRoyal

Percentage reduction is how much a quantity has reduced, relative to another quantity.

Her percentage reduction in time is 20%

Let

[tex]v_1 \to[/tex] average speed on Monday

[tex]v_2 \to[/tex] average speed on Tuesday

From the question;

[tex]v_2 = v_1 \times (100\% + 25\%)[/tex] ---- 25% greater

[tex]v_2 = v_1 \times (125\%)[/tex]

[tex]v_2 = v_1 \times 1.25[/tex]

[tex]v_2 = 1.25v_1[/tex]

The percentage reduction from v2 to v1 is:

[tex]\% v = \frac{v_2 -v_1}{v_2}[/tex]

[tex]\% v = \frac{1.25v_1 -v_1}{1.25v_1}[/tex]

[tex]\% v = \frac{0.25v_1}{1.25v_1}[/tex]

[tex]\% v = \frac{0.25}{1.25}[/tex]

[tex]\% v = 0.2[/tex]

Represent as percentage

[tex]\% v = 0.2 \times 100\%[/tex]

[tex]\% v = 20\%[/tex]

Hence, the percentage reduction is 20%

Read more about percentage change at:

https://brainly.com/question/8011401

Otras preguntas