Sorry, let me start over the correct two are:

What do you get when you pollinate a diploid (2n=38) tree with hexaploid (2n=114) tree pollen, and vice versa?
What do you get if you then backcross those two resulting hybrids with the original diploid (2n=38) tree?

I read a little more and I think the hybrids of the above would be (2n=76), right? Would this hybrid have viable seed and pollen? And does it have a name (ie. hexaploid, diploid etc.)?

I guessing the backcross would be (2n=57) right? Same on the backcross, Would this hybrid have viable seed and pollen? And does it have a name (ie. hexaploid, diploid etc.)?

Any help would be very appreciated in this, I'm new to hybridizing and very interested.

This is basically what I'm wondering, fill in the blanks:

The Hybrid: diploid (2n=38) x hexaploid (2n=114) = _________(2n=76)

Backcross: diploid (2n=38) x __________(2n=76) = __________(2n=57)

Also, how does two species with different number of chromosomes cross in meiosis/fertilization? Seems like it won't work, but I know this specific hybrid has crossed before, I just don't know how.
Any help would be very appreciated.

"Also, how does two species with different number of chromosomes cross in meiosis/fertilization?"

Usually because they are the same species**, one is just a polyploid variety, or, in some cases, the chromosome count is different because of a fusion/fission event in one ancestry. Karyotype polymorphism is not overly important compared to other factors.

**species is fluid in some organisms. Say, the mints ;-)

The answer depends on the species involved.

For example, Prunus cerasifera (2x=16) x P. domestica (6x=48) gives a hybrid that behaves like a regular allotetraploid with all bivalents.

In other words, that hybrid is a fertile tetraploid.

Sometimes, a cross between a polyploid and a diploid may give an occasional diploid among the offspring. And sometimes a seedling will turn up with the same chromosome count as the polyploid parent. Both have been reported in crosses between diploid and octoploid strawberries.

Karl

Here is a link that might be useful: Strawberry Hybrids