Hi there^_^
The formula is
A=p (1+rt)
We need first to find the number of days till the partial payment
From December 10 till January 8
December (31-10) 21+8 January
There are 29 days so
A=145,000×(1+0.135×(29÷365))
A=146,555.27
Now subtract 55000
A=146,555.27−55,000
A=91,555.27
After that find the amount due on the maturity date
The rest of the days
75-29=46 days
A=91,555.27×(1+0.135×(46÷365))
A=93,112.96 amount due after 75 days
Hope it helps