Question 1018957
Lets call the percent of the money invested in the 2% account "x" which means the percent invested in the 3% account is "1-x" (this makes sense because if we add together x and 1-x, we just get 1 meaning the total 100% of the money).

Depending on different values of p, we get different amounts of money at the end. If we find the value of p that makes $1600 we solve the problem.

If we invest $A at a interest rate of B per year, we make A*B money in interest. 

So, the formula for the money we make in interest is

{{{60000*x*.02 + 60000*(1-x)*.03 = 1600}}}

Solving this for x can be done like this

{{{x*.02 + (1-x)*.03 = 1600 / 60000}}} Dividing by 60000
{{{x*.02 + .03 - .03 * x = .0266666}}} Expand (1-x) * .03 by multiplying both by .03
{{{-.01 * x = -.003333}}} Add the x terms together and subract the .03 from the other side.
{{{x=0.33333}}} divide both sides by -.01

So 33.33% (one third) of the money was invested in the 2% interest account. To double check, if we plug this number in for x in the first equation we should see that we get $1600.