He is 38 kg.
I'll use only the first letters of their names, to make it simpler:
S+L=54.75
S+M=105
M=4L
S+4L=105
105-54.75=4L-L=3L
L=50.25/3=16.75
S=54.75-16.75=38
Alright, so we'd use the combinations with repetition formula, so we choose from 4 schools to distribute to and distribute 8 blackboards. It's then
( 8+4-1)!/8!(4-1)!=11!/(3!*8!)=165
For at least one blackboard, we first distribute 1 to each school and then have 4 blackboards left, getting (4+4-1)!/4!(4-1)!=7!/(4!*3!)=35
Answer:
0.0000805
Step-by-step explanation:
= 0.0000805