*formula*
(Number of beds)lwh/soil cubed
*substituted*
4 x 10 x 5 x 1.5/1.5
(4x10)
40 x 5 x 1.5/1.5
(40 x 5)
200 x 1.5/1.5
(Here you can do two things continue with current bedmas, or get rid of things that cancel each other out)
*continuing*
(200 x 1.5)
300/1.5
200
Therefore
She would need 200 bags
If you canceled things out you would emidiatly have 200
Please let me know if my work is incorrect and I’ll correct is ASAP