First we need interest annually
[tex]\\ \sf\longmapsto I=\dfrac{PRT}{100}[/tex]
[tex]\\ \sf\longmapsto I=\dfrac{150000(6.6)}{100}[/tex]
[tex]\\ \sf\longmapsto I=1500(6.6)[/tex]
[tex]\\ \sf\longmapsto I=9900[/tex]
Now monthly interest
[tex]\\ \sf\longmapsto \dfrac{9900}{12}[/tex]
[tex]\\ \sf\longmapsto 825[/tex]
Monthly principal=150000/12=12500
Monthly payment=12500+825=13325$
