Question 1195103

John had a total of 319 blue and red envelopes. If 1/3 the number of blue envelopes was the same as 2/5 the number of red envelopes, how many blue envelopes did he have?
<pre>Let number of blue envelopes be B
Then number of red envelopes = 319 - B
As {{{1/3}}} of the blue is the same as {{{2/5}}} of the red, we get: 
{{{matrix(2,3, (1/3)B, "=", (2/5)(319 - B), B/3, "=", 2(319 - B)/5)}}}
 5B = 6(319 - B) ----- Cross-multiplying
 5B = 1,914 - 6B
11B = 1,914</pre><pre>Number of blue, or {{{highlight_green(matrix(1,5, B, "=", "1,914"/11, "=", highlight(174)))}}}</pre>