don't show 45 min hint, if min is 15, 20 or 40

does not show 45 min hint only if min is 30
example: [telling_time_2.html?problem=set-hands-20-minute](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/telling_time_2.html?debug&problem=set-hands-20-minute)
Merge pull request #55040 from mauk81/patch-2

don't show 45 min hint, if min is 15, 20 or 40
I can't stand the capitalization of "Cubic Units"

So just get rid of it. None of the other problem types have units specified.

Auditors: emily
Add more variety to scaling vectors exercise

Vector doesn't always start at 0, 0 and can be scaled by a wider variety of values.
See Sal's comments in https://docs.google.com/a/khanacademy.org/document/d/1o-Ugr-tjw2EXjJRsPX-1LFkmn4LEW6nM6g8l--XGLYU/edit?disco=AAAAAGVQGYA#

Test plan: reload a bunch in local mode and answer questions

Auditors: alpert
Actually add all of the additional variety to scaling_vectors that I mean to

This line got lost in a merge confliect between a stash and some really old version I had checked out from a year ago (don't ask)

Test plan: reload a few times in local mode to see -a, 1/2a, etc.

Auditors: alpert
Make subtracting_fractions less computationally intensive

See https://docs.google.com/a/khanacademy.org/document/d/1Ff0WTSkoxxFhQ_6BWcZpEKHSccMT6uUz_m-qVG0CzJU/edit?disco=AAAAAGVNsIw#

Test plan: load a few problems in local mode

Auditors: alpert
Make box plots vary in number, also easier to use

Summary: Thanks http://blog.mrmeyer.com/?p=17544 for pointing this out.

Reviewers: eater

Differential Revision: http://phabricator.khanacademy.org/D3174
Fix Q3 off-by-one error

Auditors: eater
Simplify wording of solving_quadratics_by_factoring.*

See: https://docs.google.com/a/khanacademy.org/document/d/1h_0ckPG4qaEbdBk8vWu5AoWjc_1i7G3_O9U6-1ngddk/edit#heading=h.hsxmn3sc3c2f

Auditors: alpert
Merge branch 'master' of github.com:Khan/khan-exercises
Move question above the fold in reading bar charts

Auditors: emily

CC: ben
Merge remote-tracking branch 'upstream/master'
Fix graphie lines when x and y range are different.

Summary: Also, Show "-1" on graph.

Test Plan:
I've verified this works in Perseus's interactive graph. I
tried multiple x and y scales, and the lines work (both normal and extended).
Since this is touching a lot of graphs, I'm going to need to check some
other exercises. Any suggestions on exercises to look at?

Reviewers: alpert, emily

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D3106
matching solution to answer option, fix: #55743 and many duplicates

solution does not match answer option
Merge pull request #56128 from mauk81/patch-3

matching solution to answer option, fix: #55743 and many duplicates
Fix </var>
Typeset math in the check answer message.

Test plan: Answer 18.84 to http://localhost:8000/exercises/radius_diameter_and_circumference.html?seed=176&problem=circle-d-to-c&debug

Auditors: alpert, emily
Remove 'dollar' answer type

Auditors: eater
Don't require % on z-scores exercises

Auditors: eater

CC: jace
Remove most uses of percent answer type

Auditors: eater