HS SAC 2011

[qwerty123]

52. 1+3+6+10+15+...+28

58. [unparseable or potentially dangerous latex formula]

and

78. Change [unparseable or potentially dangerous latex formula] to a base 4 decimal

oh! and there was this question:

If [unparseable or potentially dangerous latex formula] is written as the mixed number [unparseable or potentially dangerous latex formula] then [unparseable or potentially dangerous latex formula] is?

I know you do [unparseable or potentially dangerous latex formula], but what do I do if it asks me for [unparseable or potentially dangerous latex formula] or [unparseable or potentially dangerous latex formula]?

[PokémonMaster]

# 52 is the sum of consecutive triangular numbers. The formula for that is [unparseable or potentially dangerous latex formula], where x is the xth triangular number (the largest one)

#58 is the sum of the reciprocals of triangular numbers. If the last triangular reciprocal here is n, to find the sum of all of them is [unparseable or potentially dangerous latex formula]

For #78, the denominator,16, denotes that there are 2 decimal places (because [unparseable or potentially dangerous latex formula]). Then, just take 7 in base 4. The answer should be [unparseable or potentially dangerous latex formula].

And for that last one, don't worry about it. They never ask for anything except for B.

Sorry if anything was unclear.

[nsguy1350]

It would never ask for A and C anyways, since they are too easy (and C isn't a number.)

For that example, [unparseable or potentially dangerous latex formula].
[unparseable or potentially dangerous latex formula] because you'll have [unparseable or potentially dangerous latex formula] in the expanded numerator and [unparseable or potentially dangerous latex formula] in the expanded denominator.

[101dalmatians]

This trick helped me a lot - got me 9 pts on like all the tests i have taken at meets this year!