Question

A pack of cinnamon scented pencils sells for $4.00. What is the sales tax rate of the total cost of the pencils is $4.32

Answer 1

To get the answer we can use proportion. We know that 4$ its 100% and 4.32 its 100% + taxes.
4$ ---------- 100%
4.32 -------- x
crossmultiply now
4x=4.32*100%
4x=432%     /:4
x=108%
We know that 4.32 its 100% + taxes=108% so to get taxes we have to subtract 108-100.
108%-100%=8% - its the answer.