Answer:
![77.7\text{ \%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/74l8eqr65rqmqb1g4lfxa966pfgwlhgtjn.png)
Step-by-step explanation:
Here, we want to get the current grade
The total grade worth that he has worked on is:
![\text{ 12\% + 20\% + }5\text{\% = 37\%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/iaf31j57eif0anppewmx132r6om4d5nxl0.png)
Now, let us calculate how much of these points he has:
For the 20% worth, he has:
![(68)/(100)*\text{ 20\% = 13.6 \%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/u9f584jag318jx07t1p4j3i8dxg4ttx7rw.png)
For the 12%, we have:
![(90)/(100)*\text{ 12= 10.8\%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/6vbhnp5xtpg47zx1saf1u3xtj53n0xmyph.png)
For the 5%, he scored 87%, we have it that:
![(87)/(100)*\text{ 5\% = 4.35\%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/j88uqr8x4lwffo4e9bhcca9s3bvcekr890.png)
The total he has now is:
![4.35\text{ + 10.8 + 13.6 = 28.75\%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/v5l9hqqcqj06urlnsfln2s90l6j8hzvldh.png)
What this mean is that he has amassed 28.75% out of the total 37%
Now, let us get this percentage
Mathematically, that would be:
![(28.75)/(37)*\text{ 100 \% = 77.7 \%}](https://img.qammunity.org/2023/formulas/mathematics/high-school/vtr7dpm8tokdcqa6m18ypbwxvlbe77f6ro.png)