Then the number b is 2x.

A number 6x

x+2x+6x=360

9x=360

x=40

So the number b =2x=80.

Quantity =6x=240

Without equations,

The number a is three times that of b, and the number b is twice that of C.

So the number a is 3×2=6 times that of c.

360÷(6+2+ 1)=40

C number =40.

B quantity =2×40=80

A number =3×80=240

I will also help you solve the equation upstairs.

3X+X+ 1/2X=360

9/2x=360

x=80

A number =80×3=240

C number =80÷2=40

Maybe you miscalculated.