In a 400-metre hurdles race the first hurdle is 45 m from the start
the last hurdle is 40 m from the finish
the rest of the hurdles are 35 m apart.

What is the total number of hurdles?

11 hurdles

Step-by-step explanation:

First hurdle = 45 m from start

Last hurdle = 40 m from finish

Other hurdles = 35 m apart

Let h = number of hurdles 35 m apart

400 = 45 + 40 + 35h

400 = 85 + 35h

400 - 85 = 35h

315 = 35h

h = 315 / 35

h = 9

Total number of hurdles = First hurdle + Last hurdle + Other hurdles

= 1 + 1 + 9

= 11 hurdles

Total number of hurdles = 11

yes

step-by-step explanation:

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.