Can any body solve this ? Please! answer fast.

If the cube is painted externally, taking the number of sections made as ‘n’,
Number of faces with no colour = $(n-2{)}^3$
Number of faces with 1 colour = $6\times (n-2{)}^2$
Number of faces with 2 colours = $12 \times (n-2)$

Here, your n is 7. So number of 1 coloured faces will be $6\times (n-2{)}^2=6{\left(7-2\right)}^2=6\times 5^2=6\times 25=150$