Container A had three times as many beads as Container B. After 30% of the beads in Container A and 15% of the beads in Container B were transferred to Container C, the number of beads in Container C increased by 35%. Given that the 3 containers had a total of 2100 beads, how many beads were there in Container B at first?
not yet dude
a+b+c = 2100
a = 3b
.30a + .15b = .35c
solve to get b=300