A says to B, "I am twice as old as you were, when I was as old as you are". Sum of their ages is 63. What are their present ages?
2007-01-31 02:13:35 · 15 answers · asked by Oracle 1 in Science & Mathematics ➔ Mathematics
"I am twice as old as you were, when I was as old as you are"
A - B = m (difference in ages)
A = 2(B - m)
A = 2(B - (A - B))
A = 2(B + B - A)
A = 2(2B - A)
A = 4B - 2A
3A = 4B (i)
Sum of their ages is 63
A + B = 63
A = 63 - B (ii)
3A = 4B
Substitute (ii) into (i)
3(63 - B) = 4B
189 - 3B = 4B
189 = 7B
B = 27
A = 63 - 27
A = 36
A = 36, B = 27
2007-01-31 02:24:39 · answer #1 · answered by Tom :: Athier than Thou 6 · 2⤊ 0⤋
21 to 42
2007-01-31 03:22:47 · answer #2 · answered by dream theatre 7 · 0⤊ 0⤋
I think the sum of their current age should be 65 instead of 63.
Currently A should be 39 and B should be 26 years old.
Therefore, when A is as old as B, that is at the age of 26 (13 years ago), B is 13, thus, A is twice as old as B when he is at the current age of B.
Nevertheless, if the sum is 63, i could not find the answer.
Manage to find the answer but with decimal place if total is 63.
A is 37.8 years old (less 12.6 years is 25.2 - same as B age now)
B is 25.2 years old (less 12.6 years is 12.6 - half of A age then)
12.6 years ago, A is at the age of B, that is 25.2 years old and B is 12.6 years old, thus A is twice as old as B.
2007-01-31 02:39:11 · answer #3 · answered by sleeping_beauty1976 2 · 0⤊ 0⤋
21 and 42
2007-01-31 05:31:23 · answer #4 · answered by Elaine 2 · 0⤊ 0⤋
21 and 42
2007-01-31 02:27:43 · answer #5 · answered by chkn_fur 5 · 0⤊ 0⤋
63 and 0
2007-01-31 02:24:26 · answer #6 · answered by Anonymous · 0⤊ 0⤋
21 and 42
2007-01-31 02:18:21 · answer #7 · answered by Ryan S 2 · 0⤊ 0⤋
21 and 42
2007-01-31 02:17:44 · answer #8 · answered by Nutty Girl 7 · 0⤊ 0⤋
A: 36
B: 27
(B was 18 nine years ago when A was 27)
In case you need to show work
A = 2(B - (A-B))
A+B = 63
these are your starting equations
So, the first equation can be rewritten as
A = 2B - 2A +2B
A = 4B - 2A
3A = 4B
A = 4B/3
By substitution in to the other equation:
4B/3 + B = 63
7B/3 = 63
7B = 189
B = 27
Now since A + B = 63
A = 36, B = 27
2007-01-31 02:19:26 · answer #9 · answered by dukebdevil93 2 · 3⤊ 0⤋
21 & 42
2007-01-31 02:20:29 · answer #10 · answered by Sally 3 · 0⤊ 0⤋