How Old Are Andy and Cal in This Mathematical Age Puzzle?

AI Thread Summary
The discussion revolves around a complex age-related problem involving two friends, Andy and Cal. The key points include the formulation of their ages based on intricate relationships defined by their current ages and future projections. The problem states that Andy's current age is equal to Cal's future age when Andy reaches a specific age, and Cal's current age is linked to Andy's past age when Cal was at a certain point in his life. Participants express confusion over the problem's complexity and the contradictory verb tenses used in the statements. There is also a technical discussion about the mathematical approach to solving the problem, specifically the use of equations to represent their ages. One participant questions the method of using C = A - X, seeking clarity on why their approach with compound functions did not yield the expected results. Overall, the conversation highlights the challenges of interpreting and solving age-related problems in mathematics.
K Sengupta
Messages
113
Reaction score
0
Two friends Andy and Cal form a team together. Andy is as old as Cal will be when Andy is twice as old as Cal was when Andy was half as old as the sum of their current ages. Cal is as old as Andy was when Cal was half as old as he will become in ten years.

Determine the respective current ages of Andy and Cal from the abovementioned statements.
 
Last edited:
Physics news on Phys.org
Assuming that 0 and 0 are not acceptable answers :wink:
Oh, didn't read that last sentence.
 
Same age :smile:
ehh nevermind :( umm cal is 8 and Andy is 6?

Work will follow later, its bedtime now.
 
Last edited:
Borek, this problem does seem more complicated that yours though.
 
Yes, in my problem total is given.
 
umm...does this even have a solution? The sentences contradict one another in regards to the verb tenses.
 
Last edited:
Andy is 40, Cal 30
Last sentence first. "was"=x, "will be"=y incremental years, respectively.
C=A-X; C-X=1/2(C+10) so X=1/2C-5 therefore C=A-1/2C+5 so 3/2C-A=5 (1)
First sentence.
A=C+Y;A+Y=2(C-X) > different X than above, just an intermediate
A-X=(A+C)/2; X=A/2-C/2. Sub into above
A+Y=2(C-A/2+C/2); Y=3C-2A
A=C+3C-2A;4C=3A;C=(3/4)A (2);
sub (2) into (1)
(9/8)A-A=5>>>>>A=40
From (2) C=30
Check:
Last sentence:
Cal is as old as Andy was > Cal is 30 and Andy was 30 10 yrs ago. 10 yrs ago Cal was 20. Is this half as old as Cal will be in 10 yrs ? Cal now 30+10 divide by 2 = 20 >>check
First sentence:
Half sum of current ages =35. Andy now 40 so this is 5 yrs ago. Cal was 25 then. Andy will be twice as old as this = 50 = 10 yrs from now. Is Andy now as old as Cal will be 10 yrs from now ? Cal is 30 +10 = 40 =Andy's age now>>check

I'd like that hour of my life back thank you
 
Last edited:
regor60 said:
Andy is 40, Cal 30
Last sentence first. "was"=x, "will be"=y incremental years, respectively.
C=A-X; C-X=1/2(C+10) so X=1/2C-5 therefore C=A-1/2C+5 so 3/2C-A=5 (1)

I'd like that hour of my life back thank you

Why did you do C = A - X? When I tried this I used compound functions--C(x) = x and A(x) = x + a--why didnt that method work?
 
  • #10
ƒ(x) said:
Why did you do C = A - X? When I tried this I used compound functions--C(x) = x and A(x) = x + a--why didnt that method work?

C=A-X just reflects the statement that "Cal is as old as Andy was..." meaning Cal's age now, C, is the same as Andy's was, meaning some years, X, before Andy's current age, A.

Further, C-X is just Cal's age X years ago, referenced to his age, C, now

I don't know what a compound function is so can't help there
 
Last edited:
Back
Top