Question 755856
The total ounces of mix is {{{ 100 + 70 = 170 }}} ounces
{{{ 3.42*100 = 342 }}} = cost of $3.42 / ounce lotion used
{{{ 14.64*70 = 1024.8 }}} = cost of $14.64 / ounce lotion used
---------------------
{{{ ( 342 + 1024.8 ) / 170 }}} = cost / ounce of  mixture
{{{ 1366.8 / 170 = 8.04 }}}
The sunscreen costs $8.04 / ounce