Answer:
10
Step-by-step explanation:
This is because 10×4=40
10+5=15
40+5=45
45/15=3
Answer:
Step-by-step explanation:
Let E and F represent Eli and his Father's current ages.
We are told that E = (1/4)F. ["Eli is now one quarter of his father’s age"]
But in 5 years, that will be:
(E+5) = (1/3)(F+5) ["In 5 years’ time his age will be one third of
his father’s age"]
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We have two equations and two unknowns. Find a way to eliminate one of the two variables and then solve for the remaining variable.
E = (1/4)F
(E+5) = (1/3)(F+5)
It seems to me the easiest would be to use the first equation's definition of E [=(1/4)F] in the second equation:
(E+5) = (1/3)(F+5)
((1/4)F+5) = (1/3)(F+5)
(1/4)F - (1/3)F = (1/3)*5 - 5
F - (4/3)F = (4/3)*5 - 20
-(1/3)F = (20/3) - (60/3)
-(1/3)F = (-40/3)
F = (120/3)
F = 40 years
E = 10 years (based on E = (1/4)F)
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In five years: F is 45 and E is 15, which would make Eli 1/3 of his father's age in 5 years.
