Question

Miss teng, a school teacher, usually walks at a speed of 0.5 m/s for y km to reach her school on time. On one cloudy day, she decided to walk the y km at a faster speed of w m/s in case it rained. If she reached her school 5 minutes earlier than usual, calculate y.

Answer 1

Answer:

$y=\frac{3w}{10\left(2w-1\right)}$

Step-by-step explanation:

We are given

Miss Teng normal walk:

speed =0.5 m/s

distance traveled =y km =y*1000

now, we can find time

we know

time = distance / speed

$t_1=\frac{1000y}{0.5}$

$t_1=2000y$

Miss Teng  walk on cloudy day:

speed =w m/s

distance traveled =y km =y*1000

now, we can find time

we know

time = distance / speed

$t_2=\frac{1000y}{w}$

If she reached her school 5 minutes earlier than usual

so,

$t_1-t_2=5\times 60 sec$

$t_1-t_2=300$

now, we can plug values

$2000y-\frac{1000y}{w}=300$

now, we can solve for y

we can multiply both sides by w

$2000yw-\frac{1000y}{w}w=300w$

$2000wy-1000y=300w$

$1000y\left(2w-1\right)=300w$

$y=\frac{3w}{10\left(2w-1\right)}$