Question 1124440
The answer is 160, but the problem is nonsensical.  

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Let x be the number Kate had originally

Then  (5/6)*(7/8)*(3/5)x = 70
        x = 70*(5/3)*(8/7)*(6/5) = 160<br>

BUT, this means Kate gave (5/6)*160 = 133.3333  CDs to Sue
Sue gave  (7/8)*133.3333 = 116.66667 CDs to Joan
Joan gave (3/5)*116.6667 = 70 CDs to Ann<br>

It is the fractional CDs that make the problem nonsensical.