Question 1204040
<br>
Tutor @josgarithmetic did not work the problem that was given....<br>
Tutor @ikleyn provided a response showing a typical formal algebraic solution.<br>
This problem can be viewed as a "mixture" problem, in which we are "mixing" an investment that returns a 2% profit with another that returns a 7% profit, yielding an average profit of 5%.<br>
Here is an unorthodox informal method for solving any 2-part mixture problem like this.<br>
Consider the three percentages (on a number line, if it helps) -- 2, 5, and 7 -- and observe/calculate that 5 is 3/5 of the way from 2 to 7.<br>
That means 3/5 of the "mixture" is the money invested in the fund that returned the 7% profit.  That "3/5" fraction means the money was invested in the two funds in the ratio 3:2, with the larger portion in the fund that returned 7% profit.<br>
Since $4000 was invested in the fund that returned a 2% profit, the amount invested in the fund that returned 7% profit can be solved using a proportion:<br>
{{{3/2=x/4000}}}
{{{x=6000}}}<br>
ANSWER: $6000 was invested in fund B<br>
All the words of explanation make this sound like a long process, but the actual calculations are quick and easy:<br>
5% is 3/5 of the way from 2% to 7%
The two amounts invested are in the ratio 3:2
The smaller amount is $4000, so the larger amount is $6000<br>
ANSWER: $6000<br>