The masses of 10 books are found to be in an arithmetic sequence. If their total mass is 13 kg and the lightest book has a mass of 400 grams, what is the mass of the heaviest book?

2,000 grams
2,100 grams
2,200 grams
2,300 grams
2,700 grams

1 answer

Sn = n/2 (a+a+(n-1)d)
If Tn is the nth term,
S10 = 5(a+T10)

13000 = 5(400+T10)
T10 = 2200

The heaviest book is 2200g