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
The answer is D. 60/100
In order to get the denominator from 5 to 100, you must multiple it by 20, meaning you also have to do that to the numerator. 3x20=60, therefore, the answer is 60/100
the fact is you cant copy and paste it you have to take screenshot or picture and attach it i don't understand the the computers substitution for unknown characters