What is the ratio of the average of first eight prime numbers to the average of first ten even natur...........

Quantitative Aptitude (CGL) Average

What is the ratio of the average of first eight prime numbers to the average of first ten even natural numbers?

This questions was previously asked in

SSC CGL 16th August 2021 Shift-2

7 : 8

1 : 7

7 : 80

8 : 70

- First, identify the first eight prime numbers: 2, 3, 5, 7, 11, 13, 17, and 19.

- Calculate their average: (2 + 3 + 5 + 7 + 11 + 13 + 17 + 19) / 8 = 9.625.

- Identify the first ten even natural numbers: 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20.

- Calculate their average: (2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20) / 10 = 11.

- Find the ratio of these averages: 9.625 : 11.

- Simplify the ratio: Multiply by 8 to clear decimals results in 77 : 88.

- Simplify further: Divide by 11, getting 7 : 8.

- Option 1: 7 : 8 - Correct, matches the simplified ratio.

- Option 2: 1 : 7 - Incorrect calculation.

- Option 3: 7 : 80 - Incorrect calculation.

- Option 4: 8 : 70 - Incorrect calculation.

Submit Error