A jar contains 100 marbles. 3/5 of the marbles are black. What fraction of the marbles are black, using 100 as the denominator?
A) 3/100
B) 90/150
C) 60/100
D) 98/100
The fraction of black marbles is 3/5. To express this fraction using 100 as the denominator, we need to multiply the numerator and denominator of the fraction by 20:
(3/5) * (20/20) = 60/100
Therefore, the fraction of black marbles, using 100 as the denominator, is C) 60/100.