Question 1086603
Mary counted 15 cupcakes left from the whole batch that Mother made for the picnic. "We've already eaten two-fifths," she shouted. How many cupcakes did Mother bake. I tried 15* 2/5 and came up with 6 eaten from the 15. I then added 6 to the 15 showing that 21 cupcakes were made. However, that seems to tell me that the two-fifths made be in error. I know that the unknown is the total amount of the cupcakes baked. Unclear as to how to find the unknown with a problem as 15 X 2/5=x  or 15 + 2/5x=x. Thank you.
<pre>No, no, no! It can't be done like that!
Since {{{2/5}}} was eaten, {{{3/5}}} of the total made, was left
This means that 15 represents {{{3/5}}} of the total number made. 
With N being the number baked, this leads to the following PROPORTION: {{{(3/5)/1  = 15/N}}}
{{{matrix(1,3, (3/5)N, "=", 15)}}} ------- Cross-multiplying
Number baked, or {{{highlight_green(matrix(1,5, N, "=", 5(15)/3, or, 25))}}}