Question 73259

First, we know that after she mixes them together, she has:
{{{2/5+9/10=4/10+9/10=13/10}}} oz of her own brand of skin cream

So, the question is:  How many 1/10 oz tubes can be produced from 13/10 ounces of her brand.  In other words, how many (1/10)'s are there in 13/10:

We can find this out by dividing 13/10 by 1/10:

{{{(13/10)/(1/10)}}} multiply numerator and denominator by 10
{{{((13/10)*10)/((1/10)*10)}}}  simplifying, we get:

{{{13/1}}} or {{{13}}}------------------------answer

Hope this helps----ptaylor