Which pair of numbers has the same gcf as that of 48 and 78

A) 4 and 34

B) 8 and 18

C) 9 and 15

D) 12 and 30

Greatest common factor is found by finding the factors of each

factors48=2 times 2 times 2 times 2 times 3

78=2 times 3 times 13

find common group

comon group=2 times 2=6

gcf=6

find others

narrow it down by crossing out any choices with numbers not divisible by 6

(crosses out A, B, C since A has 4 and B has 8 and C has 9)

therefor the answer is D, 12 and 18

check

12=2 times 2 times 3

18=2 times 3 times 3

common group=2 times 3=6

correct

answer is D, 12 and 18