Let the first part be [tex] x [/tex]
The second part is three times the first part, so it is [tex] 3x [/tex]
The third part is twice the second, so it is [tex] 2\cdot 3x = 6x [/tex]
In total, you have
[tex] x+3x+6x = 10x = 945 [/tex]
So, the first part is
[tex] x = \dfrac{945}{10}=94.5 [/tex]
The second is three times the first, so it is
[tex] 94.5 \cdot 3 = 283.5 [/tex]
The third part is twice the second, so it is
[tex] 283.5 \cdot 2 = 567 [/tex]
In fact, you have
[tex] 567 + 283.5 + 94.5 = 945 [/tex]