SOLUTION: Danny is ten years older than his sister Fiona. Danny is also twice as old as his sister Tori. How old is Danny if the sum of their ages is 50? can someone show me how to solve th

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Question 156219: Danny is ten years older than his sister Fiona. Danny is also twice as old as his sister Tori. How old is Danny if the sum of their ages is 50?
can someone show me how to solve this problem?
i can't seem to get it
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Danny is ten years older than his sister Fiona. Danny is also twice as old as his sister Tori. How old is Danny if the sum of their ages is 50?
:
Write an equation for each statement
We want to rearrange the equations so each age is in terms D
:
"Danny is ten years older than his sister Fiona."
D = F + 10
or
F = D - 10
;
" Danny is also twice as old as his sister Tori."
D = 2T
or
T = .5D
:
"How old is Danny if the sum of their ages is 50?"
D + F + T = 50"
:
Substitute (D-10) for F, and .5D for T in the total age equation:
D + (D-10) + .5D = 50
D + D + .5d = 50 + 10
2.5D = 60
D = 60%2F2.5
D = 24 yrs is Danny's age
:
Check solution:
F = 24-10
F = 14
and
T = .5(24)
T = 12
:
24 + 14 + 12 = 50; confirms our solution