According to the problem:
first calculate cost price,
Given That
SP=750
Loss=10%
Therefore, CP=SP+10% of CP
⇒CP(1−10100)=SP
⇒CP=SP×10090
⇒CP=750×10090
=25003 Rs
Now, he has to gain 5 on this cost price,
Therefore, the new selling price would be,
=25003×105100
=RS.875
Hence the answer is
875Rs