Question 274904
OK.  We need to find the Least Common Multiple (LCM) of 6, 9 & 13.  To do this we will break each of the numbers down into their prime factors:
6=3*2
9=3*3=3^2
13=1*13 
Next, we take the highest power that appears for each of the prime numbers and we get:
2, 3^2&13. Now we multiply these together to get the LCM:
18*13= 234 inches to the next point that all three frogs touch
CK 
frog 1 makes 39 jumps to get to 234 inches
frog 2 makes 26 jumps to get to 234 inches
frog 3 makes 18 jumps to get to 234 inches

Hope this helps---ptaylor