Randy had a sheep that started eating more and more as each day passed. On July 1,

Randy’s sheep ate 5 carrots. On July 2, Randy’s sheep ate 11 carrots. On July 3, the sheep ate 18 carrots. How many carrots will the hungry sheep eat on July 30th?

2 answers

July 2: 5
July 3: 11
July 4: 18
July 5: 26
July 6: 35
July 7: 45
July n: 5 + 6 +.. + (n+3)
= 4(n-1) + 1 + 2 +...+ (n-1)
= 4(n-1) + (n-1)n/2
July 30 = 4*29 + 30*29/2 = 551
Looks like you're one day off. On July 1 the sheep ate 5 carrots.

on July nth, the sheep eats n(n+9)/2 carrots.

On July 30, that's 30(39)/2 = 15*39 = 585 carrots