Question

ON wednesday Eddy goes to a velodrome to train. He cycles the first lap of the track in 25 seconds. Each lap Eddy cycles takes him 1.6 seconds longer thatn the previous lap.

Required:
a. Find the time in seconds, Eddy takes to cycle his tenth lap 2
b. Eddy cycles his last lap in 55.4 seconds. Find how many laps he has cycled on wednesday.
c. Find the total time in minutes, cycled by Eddy on Sunday.

Answer 1

Explanation:

The data of timing for each lap will form a arthmetic progression ( AP ) with first term as 25 s and common difference of 1.6 s .

a )

first term a = 25

common difference d = 1.6 .

10 th term of the series can be given by following formula

a₁₀ = 25 + ( 10-1 ) x 1.6

= 25 + 1.6 x 9

= 39.4 s

b )

Let n th be the last lap

a(n) = a + ( n-1 ) x d

55.4 = 25 + ( n- 1 ) x 1.6

n - 1 = 19

n = 20 .

c )

sum of all the term of AP

=( first term + last term ) x no of term / 2

= (25 + 55.4 ) x 20 / 2

= 804 s .

= 804 / 60 min

= 13.4 min .