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

see explanation

step-by-step explanation:

since the sequence is geometric there is a common ratio r between consecutive terms, that is

r = 4 ÷ - 2 = - 2

r = - 8 ÷ 4 = - 2

r = 16 ÷ 8 = - 2

the next term - 13 must be incorrect as it should be - 32 for the sequence to be geometric.

the first 4 terms are therefore geometric with common ratio r = - 2

b is 38 degrees.

a is 52 degrees.

this is because if b is 38 and a is 14 degrees more than b than 38+14=52 and 52+38=90 degrees. hope this .