Number sense question

[RobinK]

Is there an easier way to find the remainder instead of just dividing it out? 112358/6 has a remainder of ___ Answer: 2

How many 2-element or 3-element subsets does the set { e, m, p, t, y } have? Answer: 20

12345 x 8 + 5 = ___ Answer : 98765

[martillaso]

1) Add up 1+1+2+3+5+8=20 then divide 20 by 6 and you get r2

2) I did
{5 \choose 2} + {5 \choose 3} = 20, but I'm not too sure if that's the right step

[BlasianAsian]

Does that adding up trick work for any other number besides 6 and 9?

[qwerty123]

[unparseable or potentially dangerous latex formula] is correct because it's just asking how many ways can you split the set up to 2 or 3 elements.

@BlasianAsian: the trick also works with 3

Oh and just multiply it out for the last one. (that's what i do)

[101dalmatians]

[nsguy1350]

[BlasianAsian]

LoL, forgot that it works with three. Thanks for clarifying.