Seven years ago Bob was k times as old as Ann. If

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BTGModeratorVI wrote:
Wed Feb 26, 2020 4:25 pm
Seven years ago Bob was k times as old as Ann. If Ann is now 11 years old, what is Bob’s present age in terms of k?

A. 7 + 4k
B. 11/k + 7
C. 11 - 7/k
D. 11 - k/7
E. 4k - 7

Answer: A
Source: Magoosh
Say the present age of Bob and Ann are B and A, respectively.

Thus, B – 7 = k(A – 7) => B = k(A – 7) + 7 = k(11 – 7) + 7

B = 4k + 7

The correct answer: A

Hope this helps!

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BTGModeratorVI wrote:
Wed Feb 26, 2020 4:25 pm
Seven years ago Bob was k times as old as Ann. If Ann is now 11 years old, what is Bob’s present age in terms of k?

A. 7 + 4k
B. 11/k + 7
C. 11 - 7/k
D. 11 - k/7
E. 4k - 7

Answer: A
Source: Magoosh
If Ann is NOW 11 years old, then 7 YEARS AGO, Ann was 4 years old.

Seven years ago Bob was k times as old as Ann.
So, 7 YEARS AGO, Bob's age was 4k

What is Bob’s present age in terms of k?
To find Bob's present age, we need to add 7 to his age 7 years ago.
So, Bob's PRESENT age = 4k + 7

Answer: A

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BTGModeratorVI wrote:
Wed Feb 26, 2020 4:25 pm
Seven years ago Bob was k times as old as Ann. If Ann is now 11 years old, what is Bob’s present age in terms of k?

A. 7 + 4k
B. 11/k + 7
C. 11 - 7/k
D. 11 - k/7
E. 4k - 7

Answer: A
Source: Magoosh
Letting B and A equal Bob’s and Ann’s current ages, respectively, we can create the equation:

B - 7 = k(A - 7)

Since A = 11, we have:

B - 7 = k(11 - 7)

B - 7 = 4k

B = 4k + 7

Answer: A

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