SOLUTION: Aaron is four more than one-half as old as Hunter. Kevin is thirty-one less than four times the age of Aaron. In five years, Kevin will be twenty-five less than three times the age

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Aaron is four more than one-half as old as Hunter. Kevin is thirty-one less than four times the age of Aaron. In five years, Kevin will be twenty-five less than three times the age      Log On

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Question 1093907: Aaron is four more than one-half as old as Hunter. Kevin is thirty-one less than four times the age of Aaron. In five years, Kevin will be twenty-five less than three times the age of Aaron. How old is Kevin?
Found 3 solutions by josmiceli, ikleyn, MathTherapy:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = Aaron's age now
Let +b+ = Hunter's age now
Let +c+ = Kevin's age now
--------------------------------
(1) +a+=+%281%2F2%29%2Ab+%2B+4+
(2) +c+=+4a+-+31+
(3) +c+%2B+5+=+3%2A%28+a+%2B+5+%29+-+25+
--------------------------------
(1) +2a+=+b+%2B+8+
(1) +2a+-+b+=+8+
and
(3) +c+%2B+5+=+3a+%2B+15+-+25+
(3) +c+=+3a+-+15+
---------------------
Subtract (2) from (3)
(3) +c+=+3a+-+15+
(2) +-c+=+-+4a+%2B+31+
-----------------------
+0+=+-a+%2B+16+
+a+=+16+
and
(1) +2a+-+b+=+8+
(1) +2%2A16+-+b+=+8+
(1) +32+-+b+=+8+
(1) +b+=+24+
and
(3) +c+=+3a+-+15+
(3) +c+=+3%2A16+-+15+
(3) +c+=+48+-+15+
(3) +c+=+33+
----------------------
Kevin is 33 now
----------------------
check:
(1) +a+=+%281%2F2%29%2Ab+%2B+4+
(1) +16+=+%281%2F2%29%2A24+%2B+4+
(1) +16+=+12+%2B+4+
(1) +16+=+16+
OK
you can check (2) and (3)

Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
.
Aaron is four more than one-half as old as Hunter. Kevin is thirty-one less than four times the age of Aaron.
In five years, Kevin will be twenty-five less than three times the age of Aaron. How old is Kevin?
~~~~~~~~~~~~~~~~~~~~~~

From the condition, you have these two equations

K = 4A - 31,              (1)
K+5 = 3*(A+5)-25.         (2)

Substitute K from (1) into (2) to get an equation for A:

(4A-31) + 5 = 3*(A+5) - 25,

4A - 26 = 3A - 10,

4A - 3A = 26 - 10 = 16  ====>  A = 16.


Aaron is 16 years old now.
Kevin is 4*A - 31 = 4*16-31 = 64-31 = 33.


Answer.  Kevin is 33 years old now.

The info related to Hunter is not relevant to the question.



Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Aaron is four more than one-half as old as Hunter. Kevin is thirty-one less than four times the age of Aaron. In five years, Kevin will be twenty-five less than three times the age of Aaron. How old is Kevin?
Hunter has absolutely nothing to do with this problem, so info about him is excessive and unnecessary.
Let Aaron's age be A, and Kevin's, K
Then K = 4A - 31
We're also given that: K + 5 = 3(A + 5) - 25 =====> K + 5 = 3A + 15 - 25
K = 3A - 15
We then get: 4A - 31 = 3A - 15
4A - 3A = 16
A, or Aaron is: 16 years-old
Kevin is: