Math
posted by Ben Eckman on .
In preparation for a party, Heather fills a jar with gumdrops. Before the party begins, Erik sees the gum drop jar, he (hoping that no one will realize) takes onethird of the drops. Soon after sonia takes takes onethird of the gumdrops(she too, hopes that no one will notice). Finally, neel appears and like the others he takes one third of the gumdrops. if forty are left in the jar, how many did it originally contain?

There were x gumdrops at the start.
After Erik raided the jar, there were 2x/3 drops.
After Sonia, there were 4x/9 drops
After Neel, there were 8x/27, which was 40
So, 8x/27 = 40
x = 135.
check:
Erik got 1/3 * 135 = 45, leaving 90
Sonia got 1/3 * 90 = 30, leaving 60
Neel got 1/3 * 60 = 20, leaving 40