Answer:
There are 4 common factors of 30 and 72, that are 1, 2, 3, and 6. Therefore, the greatest common factor of 30 and 72 is 6.
Step-by-step explanation:
84/18=14/3
60/32=15/8
4x+ 3 = 3(2x-5) ;x=2; x^{2} = 4
If you doing straight-line depreciation rate
(P-s)÷N
(24000-18000)/5=1200
where p is cost, s is sold or salvage value, N is number of years

Therefore, the diameter is twice of that:
52 centimeters.