Question 695101
let h = husband's present age
let w = wife's
let s = son's
:
Write an equation for each statement:
:
The average age of a husband, wife and their son, 3 years ago was 27 years
{{{((h-3)+(w-3)+(s-3))/3}}} = 27
Multiply both sides by 3
h + w + s - 9 = 3(27)
h + w + s = 81 + 9
h + w + s = 90
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and that of the wife and son 5 years ago was 21 years.
{{{((w-5)+(s-5))/2}}} = 21
mult by 2
w + s - 10 = 2(21)
w + s = 42 + 10
w + s = 52
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In the 1st equation, replace w + s with 52
h + 52 = 90
h = 90 - 52
h = 38 yrs is the husband's age
:
:
Check this
{{{((38-3) + (52-6))/3}}} = 27