SOLUTION PLZ

Question

Leaving home at same time if maria walks to school at 3 km/hr she reaches 10 minutes late if she cycles to school at 6 km/hr she reaches 15 minutes early.How far is the school from her home?

Answer 1

Hi Nick,

 

the time it takes for Maria to get to school by walking is 25 more minutes than by cycling (the difference in being 10 minutes late and 15 minutes early is 25)

 

time = distance/speed

 

because the speeds are in km/hour the 25 minutes needs to be converted to hours by dividing by 60

 

let x = distance

 

speed = 3 when walking

 

speed = 6 when cycling

 

x/3 = x/6 +25/60

 

multiply everything by 60 to clear the fractions

 

20x = 10x + 25

 

10x = 25

 

x = 2.5

 

2.5 km

 

 

Answer 2

d = rt, the distances are equal, and t is in hours.

 

3(t + 1/6) = 6(t - 1/4)

3t + 1/2 = 6t - 3/2

3t = 2

t = 2/3

 

3(2/3 + 1/6) = 3(4/6 + 1/6) = 3(5/6) = 15/6 = 2 1/2 km

 

or, 6(2/3 - 1/4) = 6(8/12 - 3/12) = 6(5/12) = 30/12 = 2 1/2 km