The maximum Youth Allowance is reduced by $1 for every $4 that the youth's parents income is over $31 400. By how much is Hannah's Youth Allowance reduced if her parents earn a combined income of $35 624?

1 Answer
Jul 29, 2018

Hannah's reduction in Youth Allowance is $2112$2112

Explanation:

Let the total income be tt

Then the amount over $31400" "$31400 is " "$[t-31400] $[t31400]

The count of every every $4 in $[t-31400] -> ($[t-31400])/($4)$[t31400]$[t31400]$4

Notice the way in which the units of measurement ($) cancels out leaving just a count: color(white)("d")-> color(white)("d") (cancel($)[t-31400])/(cancel($)4)

We are told that the actual joint income is $35624.00

This is substituted for t: color(white)("d")-> (35624-31400)/4 = 2112

For each of these counts the youth allowance is reduced by $1

Total reduction in Hannah's allowance is: $1 xx 2112 = $2112