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Of the three numbers, the first is twice the second and the second is 3 times the third. If their average is 100, the largest of the three numbers is :
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- 120
- 150
- 180
- 300
- 120
Correct Option: C
Let the third number be n.
∴ Second number = 3n
First number = 6n
∴ average of three numbers = 100
⇒ (n + 3n + 6n) = 100 × 3
⇒ 10n = 300
⇒ n = 30
∴ The largest number = 6n = 6 × 30 = 180
Second method to solve this question with the help of given formulas :
a = 2, b = 3, X = 100
| Largest number = | × X | |
| 1 + b + ab |
| Largest number = | × 100 | |
| 1 + 3 + 2 × 3 |
| Largest number = | = 180 | |
| 10 |
