Simplify first the given:
Balance = $1942
APR = 16.8%
New Transaction = $280
Since APR is annual percentage rate of charge
Let us first add the two transactions:
$1942 + $280 = $2,222 this is now the new remaining balance
We’ll get the 16.8% of the $2,222 and add it.
$2,222 + 16.8% = 2,595.296 = $2,595.30