Direction: Study the given information carefully and answer the questions. The family consist of seven members A, B, C, D, E, F, G are of different ages and arranged them from the highest age to youngest. Consecutively arranged person’s age difference is only 3.
What is the age of A?
58
This problem requires us to determine the specific age of family member A by carefully analyzing the given information about seven family members (A, B, C, D, E, F, G). The members are ranked by age from oldest to youngest, with a consistent age difference between consecutive individuals.
We are told that the seven family members are arranged by age, and the age difference between consecutive people is exactly 3 years. This setup indicates an arithmetic progression for their ages.
Let the ages from oldest to youngest be represented as $a_1, a_2, a_3, a_4, a_5, a_6, a_7$. The common difference ($d$) is 3.
We know the youngest person's age is 46. Therefore, $a_7 = 46$.
The formula for the $n$-th term in an arithmetic sequence is $a_n = a_1 + (n-1)d$. Since ages are decreasing, we can think of it as $a_n = a_1 - (n-1) \times 3$ or use $d=-3$. Using $a_7 = 46$ and $n=7$ with the common difference of 3:
$$a_7 = a_1 - (7-1) \times 3$$
Substituting the known value for $a_7$:
$$46 = a_1 - 6 \times 3$$
$$46 = a_1 - 18$$
Solving for $a_1$ (the age of the oldest person):
$$a_1 = 46 + 18$$
$$a_1 = 64$$
With the oldest person being 64 and the common difference being 3, we can list all the ages:
| Rank (Oldest to Youngest) | Age |
|---|---|
| 1st | 64 |
| 2nd | 61 |
| 3rd | 58 |
| 4th | 55 |
| 5th | 52 |
| 6th | 49 |
| 7th | 46 |
Now, let's apply the specific clues to identify A's age:
Let's examine the remaining possibilities for A's age:
If A is 49, then D and E must both be younger than 49. The only available age younger than 49 is 46. Since D and E are different people, they cannot both be 46. Thus, A cannot be 49.
If A is 52, then D and E must be younger than 52. The available ages younger than 52 are 49 and 46.
Given $E < D$, D must be 49 and E must be 46.
Let's check the other conditions:
If A is 58, then D and E must be younger than 58. The available ages younger than 58 are {55, 52, 49, 46}.
We know D's age is not 55. So, D's possible ages are {52, 49, 46}.
We also know $E < D$. Let's test the possibilities for D:
The only scenario that satisfies all conditions is when A's age is 58.
After evaluating all the given conditions and possibilities, the age of A is determined to be 58 years.
Who is third oldest among them?
Who among the following person’s age is 55?
Who is the youngest person?
How many person(s) is/are younger to D?
Who is third oldest among them?
Who among the following person’s age is 55?
Who is the youngest person?
How many person(s) is/are younger to D?
In a class of 35 children, Ameya’s rank is sixth from the top. Annie is seven ranks below Ameya. What is Annie’s rank from the bottom?