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
1. Given a group of n people. There are C(n, r) ways of forming groups of r out of n.
2. Where C(n, r)=

3. For example, given {Andy, John, Julia}. We want to pick 2 people to give a gift: we can pick {(Andy, John), (Andy, Julia), (John, Julia)}, so there are 3 ways. So we can list and count.
4. Or we could do this with the formula C(3, 2)=

5. C(8, 6)=

So there are C(8,6)=28 ways of chosing 6 out of 8 people to form the subcommittees. <span />
Let x = taxable income = difference of gross income and deductions T = income tax paid = amount sent to the government Use the "filing jointly" chart on the right side. You'll use the second row of that chart since subtracting $72,380.90-$8,295.00 leads to a value between 16750 and 68000. That second row turns into this equation T=1675+0.15(x-16750<span>) w</span>here <span>16750<x≤68000</span>