Khan/khan-exercises

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 b40264c Adding in my initial prototype. jeresig authored May 9, 2011 1 1e052cf Word problem helper library spicyj authored May 25, 2011 2 b40264c Adding in my initial prototype. jeresig authored May 9, 2011 3 72418b8 Add meta charset to all HTML pages. jeresig authored Jul 28, 2011 4 07d95d3 Rename EVERYTHING; closes #323. spicyj authored Jul 22, 2011 5 Rate problems 1 7af06f8 Move all exercise logic and file loading into JS file. Move exercises… jeresig authored May 10, 2011 6 b40264c Adding in my initial prototype. jeresig authored May 9, 2011 7 8 190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 9
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11 11 + rand(9) 12 41 + rand(9) 13 31 + rand(9) 14 1 + rand(9) 15 AVG * TIME 16 (SPEED1 * SPEED2 * TIME - DIST * SPEED2) / (SPEED1 - SPEED2) 17 DIST - DIST2 18
cf02179 Strip trailing whitespace spicyj authored Jun 1, 2011 19 190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 20
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1e052cf Word problem helper library spicyj authored May 26, 2011 23

person(1) traveled by vehicle(1) at an average speed of SPEED1 miles per hour.

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Then, he(1) traveled by vehicle(2) at an average speed of SPEED2 miles per hour.

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In total, he(1) traveled DIST miles for plural(TIME, "hour").

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 26
1e052cf Word problem helper library spicyj authored May 26, 2011 27

How many miles did person(1) travel by vehicle(1)? (Round to the nearest mile.)

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 28

round(DIST1)

a74d029 Show final answer in rate problems 1 (fix #165) spicyj authored Jul 18, 2011 29
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d_vehicleVar(1) = round(DIST1) miles

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190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 32
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1e052cf Word problem helper library spicyj authored May 26, 2011 34

How many miles did person(1) travel by vehicle(2)? (Round to the nearest mile.)

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 35

round(DIST2)

a74d029 Show final answer in rate problems 1 (fix #165) spicyj authored Jul 19, 2011 36
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d_vehicleVar(2) = round(DIST2) miles

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190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 39
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1e052cf Word problem helper library spicyj authored May 26, 2011 41

How many minutes did person(1) travel by vehicle(1)? (Round to the nearest minute.)

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 42

round(DIST1 / SPEED1 * 60)

a74d029 Show final answer in rate problems 1 (fix #165) spicyj authored Jul 19, 2011 43
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t_vehicleVar(1) = round(DIST1 / SPEED1 * 60) minutes

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190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 46
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1e052cf Word problem helper library spicyj authored May 26, 2011 48

How many minutes did person(1) travel by vehicle(2)? (Round to the nearest minute.)

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 49

round(DIST2 / SPEED2 * 60)

a74d029 Show final answer in rate problems 1 (fix #165) spicyj authored Jul 19, 2011 50
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t_vehicleVar(2) = round(DIST2 / SPEED2 * 60) minutes

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b40264c Adding in my initial prototype. jeresig authored May 9, 2011 53
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cf02179 Strip trailing whitespace spicyj authored Jun 2, 2011 55 190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 56
f1c3306 Make MathJax pretty! (fix #212) spicyj authored Jul 26, 2011 57

Remember that d = r * t, or written another way, t = d / r.

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 58
1e052cf Word problem helper library spicyj authored May 26, 2011 59

d_vehicleVar(1) = distance that person(1) traveled by vehicle(1)

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d_vehicleVar(2) = distance that person(1) traveled by vehicle(2)

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Total distance: d_vehicleVar(1) + d_vehicleVar(2) = DIST

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 62
1e052cf Word problem helper library spicyj authored May 26, 2011 63

Total time: t_vehicleVar(1) + t_vehicleVar(2) = TIME

cf02179 Strip trailing whitespace spicyj authored Jun 2, 2011 64

t_vehicleVar(1) = (d_vehicleVar(1) / SPEED1) and 1e052cf Word problem helper library spicyj authored May 26, 2011 65 t_vehicleVar(2) = (d_vehicleVar(2) / SPEED2)

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 66

Substitute the blue equations for: 1e052cf Word problem helper library spicyj authored May 26, 2011 67 (d_vehicleVar(1) / SPEED1) + (d_vehicleVar(2) / SPEED2) = TIME

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 68

Multiply the above equation by -1 * SPEED1: 1e052cf Word problem helper library spicyj authored May 26, 2011 69 -d_vehicleVar(1) - (SPEED1 / SPEED2) * d_vehicleVar(2) = -SPEED1 * TIME

190610b Retool framework, move Math and Graph logic out of khan-exercise.js a… jeresig authored May 18, 2011 70

Add the two orange equations for: 1e052cf Word problem helper library spicyj authored May 26, 2011 71 (SPEED2 - SPEED1 / SPEED2) * d_vehicleVar(2) = DIST - (SPEED1 * TIME)

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Simplify and round to the nearest integer:
73 d_vehicleVar(2) = round(DIST2) miles
74 d_vehicleVar(1) = round(DIST1) miles
75 t_vehicleVar(1) = round(DIST1 / SPEED1 * 60) minutes
76 t_vehicleVar(2) = round(DIST2 / SPEED2 * 60) minutes

b40264c Adding in my initial prototype. jeresig authored May 9, 2011 77
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79 f161590 added KhanUtil.plural pappy74 authored May 22, 2011 80
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