Answer:
1800
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
= 
[ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Here a₁ = - 27 and d = 6, thus
= 
[ (2 × - 27) + (29 × 6) ]
= 15( - 54 + 174)
= 15(120)
= 1800
Answer:
20, increased, Bianca
Step-by-step explanation:
First one:
He is shown to have travelled 20km in 1 hour, so that's 20km/h.
Second:
The gradient is how steep the curve is, the steeper the faster the person is travelling. Due to the fact Bianca's curve becomes steeper, it shows she is travelling faster. Therefore, her running speed increases.
Third:
Bianca's line hits 50km before Alberto, so therefore she finished first.
Let me know if this makes sense, hope it helped! :D
