Question

A cyclist preparing for an ultra cycling race cycled 20 km on the first day of training. SHe increases her distance by 4 km every day. 

1. On which day does she cycle 100km?
2. Determine the total distance she would have cycled from day 1 to day 14.
3. Would she be able to keep up this daily rate of increase in distance covered indefinitely? Explain your answer.

Answer 1

1. Tn=a+(n-1)d

    100=20+(n-1)4

    n= (100-20)/4 + 1

     n  = 21 , that is on day 21.

2.sum up to day 14= n(2a+(n-1)d)/2

                                 = 14(2(20)+(14-1)4)/2

                                = 644km

3.  n(2a+(n-1)4)/2

As n, number of days increases, km to be covered will be too much, hence she may not keep up.