Question: bag a contains red , white and blue marbles such that the red to white marble ratio is 1 : 3 and the white to blue marble ratio is 2 : 3 . bag b contains red and white marbles in the ratio of 1 : 4 . together , the two bags contain 28 white marbles . how many red marbles could be in bag a ?
A) 1
B) 3
C) 4
D) 6
E) 7
Correct answer: C
Grade: 7 | Topic: Ratios and proportions | Difficulty: Hard | Standard: 7.RP.A.2