Question

In a chocolate making competition niya makes 490 chocolates in 8 rounds. She made an average of 45 chocolates in all the rounds and average of 35 chocolates in rounds except those 8 mentioned previously. How many rounds did niya compete?
1. 15
2. 16
3. 29
4. 21
5. 27

Answer 1

Correct Answer - Option 4 : 21

 Given:

8 rounds = 490 chocolates

Average in all rounds = 45

Calculation:

Let total number of rounds be X not including 8 rounds

⇒ Total chocolates made = 35 × X

⇒ adding 8 rounds = 35X + 280/ (X + 8)

⇒ 35X + 490 = 45 × (X + 8)

⇒ 35X + 490 = 45X + 360

⇒ 10X = 130

⇒ X = 13

∴ Total number of rounds is 21