An investor has an account with stock from two different companies. Last year, his stock in Company A was worth $6600 and his stock in Company B was worth $3500.
The stock in Company A has increased 7% since last year and the stock in Company B
has increased 1%. What was the total percentage increase in the investor's stock
account? Round your answer to the nearest tenth (if necessary).

22.7%

Given that last year stock for company A was $7200
The stock for company B last year was worth $3510
Stock in company A decreased by 24%
This means the new value of stock for company A became;
(100-24)/100 *$7200
76/100*$7200
0.76*7200 =$5472
Stock in company B decreased by 20%
This means the new value of stock for company B became;
(100-20)/100 *$3510
80/100*$3510
0.8*$3510
$2808
Original investors stock value was = $7200+$3510 =$10710
New investors stock value is = $5472+$2808=$8280
Decrease in value of stock = $10710-$8280 =$2430
percentage decrease in stock value = decrease in stock/original value of stock *100%
=2430/10710 *100 =22.689
=22.7%

Someone else had the same problem answered
So here it is