Let the total number of camels be C. We have that (1/4) of the camels had been seen in the forest. Twice the square root of the total number had gone to the forest.

The number that remains is equal to 15.

So we have C - (1/4)*C - 2*sqrt C = 15

=> (3/4)*C - 2*sqrt C = 15

=> 3C - 8* sqrt C = 60

=> 3C - 60 = 8*sqrt C

=> 9C^2 + 3600 - 360C = 64C

=> 9C^2 - 424C + 3600 = 0

C = [-b + sqrt (b^2 - 4ac)]/2a

=> [ 424 + sqrt (424^2 - 4*9*3600)]/18

=> 36

The other root is a fraction and can be ignored,

**The total number of camels is 36.**