Toy John and Ken are reading a book . Toy reads a book every 3 days, John reads a book every 7 days and Ken reads a book every 9 days. If they are reading together now, how long it take to read a book together again?
Toy John and Ken are reading a book .Toy reads a book every 3 days, John reads a book every 7 days and Ken reads a book every 9 days. If they are reading together now, how long it take to read a book together again?