Question 150401: Can you please help me solve this problems:
1.) Erwin is 5 times older than john and John is twice as old as his sister, Alice. In 2 years time, the sum of their ages will be 58. How old is john now?
2.) John is twice as old as his friend peter. Peter is 5 years older than Alice. In 5 years, John will be three times as old as Alice. How old is Peter?
3.) Reggie is 5 years older than Lani. Five years ago, the sum of their ages is 25. How old are they now?
Answer by mangopeeler07(462)   (Show Source):
You can put this solution on YOUR website! 1. Erwin is 5 times older than john and John is twice as old as his sister, Alice.
Erwin=5j
John=j; 2a
Alice=a; 1/2j
Use j, since all of the people can be expressed in terms of j.
In 2 years time, the sum of their ages will be 58.
5j+2+j+2+1/2j+2=58
Combine like terms
6.5j+6=58
Subtract 6
6.5j=52
Divide by 6.5
j=8
Erwin=5(8)
John=(8)
Alice=1/2(8)
5(8)+(8)+1/2(8)+6=58
40+8+4+6=58
Erwin=40
*John=8*
Alice=4
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2. John is twice as old as his friend peter. Peter is 5 years older than Alice.
John=2p
Peter=p; a+5
Alice=p-5
Use p as the variable.
In 5 years, John will be three times as old as Alice.
2p+5=3(p-5+5)
Simplify
2p+5=3p
Subtract 2p from both sides
5=p
John=2(5)
Peter=(5)
Alice=(5)-5
John=10
*Peter=5*
Alice=0
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3. Reggie is 5 years older than Lani.
Reggie=L+5
Lani=L
Five years ago, the sum of their ages is 25.
(L+5)-5+(L)-5=25
L+L-5=25
2L-5=25
2L=30
L=15
Reggie=(15)+5
Lani=(15)
Reggie=20
Lani=15
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