Four numbers are in the ratio of 7: 8:9: 10. Sum of these number is 68. What will be the sum of the first and fourth number?

Correct option is C

Given:

The ratio of the four numbers is 7:8:9:10.

The sum of the numbers is 68.

Solution:

Find the total of the ratio terms:
Total of the ratio = 7k + 8k + 9k + 10k = 34k

k = 68 / 34 = 2

Calculate the actual numbers:
First number = 7 × k = 7 × 2 = 14
Second number = 8 × k = 8 × 2 = 16
Third number = 9 × k = 9 × 2 = 18
Fourth number = 10 × k = 10 × 2 = 20

The sum of the first and fourth numbers:
Sum of the first and fourth numbers = 14 + 20 = 34

The sum of the first and fourth numbers is 34. The correct option is C.