# publicKhan/khan-exercises

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randRange( 2, 25 )                    randRange( 3, 10 )                    randRange( 2, 12 )                    P * X + Q

{Before skateboarding camp person( 1 ) knew how to do|person( 1 ) already knows how to do} Q skateboarding tricks. {person( 1 ) hopes to one day be able to do randRange( 25, 50 ) tricks. |}{Every week, person( 1 ) will be taught P tricks.|At skateboarding camp, person( 1 ) will learn P tricks per week.}

If person( 1 ) spends X weeks at camp, how many skateboarding tricks will he( 1 ) know at the end of camp?

R skateboarding tricks

Skateboarding tricks he( 1 ) learns per week x Number of weeks at the camp + Skateboarding tricks he( 1 ) already knows = Number of tricks known at the end of camp

Skateboarding tricks he( 1 ) learns per week = P

Number of weeks at the camp = X

Skateboarding tricks he( 1 ) already knows = Q

Number of tricks known at the end of camp = r

P \cdot X + Q = r

P \cdot X + Q = R

person( 1 ) will know R tricks at the end of camp.

randRange( 1, 50 )                    randRange( 2, 12 )                    randRange( 2, 8 )                    P * X + Q

person( 1 ) has run plural( Q, "marathon" ){ and {plans|has commited to} to run P marathons per year.|. He( 1 ) {plans|is commited} to run P marathons per year.}{ person( 1 ) has been training for randRange(2, 3) months for this upcoming commitment.|}

After X years, how many marathons will person( 1 ) have run?

R marathons

Number of marathons planned per year x Number of years + Number of marathons he( 1 ) already ran = Total number of marathons

Number of marathons planned per year = P

Number of years = X

Number of marathons he( 1 ) already ran = Q

Total number of marathons = r

P \cdot X + Q = r

P \cdot X + Q = R

person( 1 ) will have run R marathons at the end of X years.

randRange( 0, 15 )                    randRange( 5, 30 )                    randRange( 2, 20 )                    P * X + Q

{person( 1 ) has a coupon for shipping from Amazon.com|person( 1 ) has decided to purchase some books from Amazon.com}. {No matter how much he( 1 ) purchases, shipping will cost $Q.|Shipping is set at a flat-rate of$Q, regardless of the number of books purchased.}

If person( 1 ) buys X books for $P each, how much will the total bill be (assuming no sales tax)? R Cost of each book x Number of books bought + Cost of shipping = Bill total Cost of each book = P Number of books bought = X Cost of shipping = Q Bill total = r P \cdot X + Q = r P \cdot X + Q = R person( 1 ) will spend$R on his(1) Amazon purchase.

randRange( 10, 100 )                    randRange( 1, 25 )                    randRange( 3, 12 )                    P * X + Q

{Q articles have been published by person( 1 ) in The New York Times|person( 1 ) has written Q articles for The New York Times}{ (Q - randRange(2, 8) of them in the last year)|}{. He( 1 ) has a new contract| and he( 1 ) has a new contract} to write plural( P, "article" ) per month for the next X months.

At the end of X months, how many articles will he( 1 ) have had published in The New York Times?

R articles

Number of articles to be written per month x Number of months writing articles + Number of articles already written = Total number of articles

Number of articles to be written per month = P

Number of months writing articles = X

Number of articles already written = Q

Total number of articles = r

P \cdot X + Q = r

P \cdot X + Q = R

person( 1 ) will have written R articles at the end of X months.

randRange( 5, 40 )                    randRange( 2, 15 )                    randRange( 2, 6 )                    P * X + Q

{After practicing for randRange( 2, 5 ) months, |}person( 1 ) {has reached proficiency|is proficient} in Q exercises on Khan Academy.

If person( 1 ) completes P exercises per week for the next X weeks, how many exercises will he( 1 ) have completed in total?

R exercises

Number of exercises to complete per week x Number of weeks completing exercises + Number of exercises already proficient in = Total number of exercises completed

Number of exercises to complete per week = P

Number of weeks completing exercises = X

Number of exercises already proficient in = Q

Total number of exercises completed = r

P \cdot X + Q = r

P \cdot X + Q = R

person( 1 ) will have completed R exercises at the end of X weeks.

randRange( 20, 40 )                    randRange( 2, 10 )                    randRange( 30, 100 )                    ceil( (R - Q) / P )

person( 1 ) sells magazine subscriptions and earns $P for every new subscriber he( 1 ) signs up. person( 1 ) also earns a$Q weekly bonus regardless of how many magazine subscriptions he( 1 ) sells.

If person( 1 ) wants to earn more than \$R this week, what is the minimum number of subscriptions he( 1 ) needs to sell?

X subscriptions

Dollars per subscription x Number of subscriptions sold + Weekly bonus > Minimum dollar amount to earn this week

Dollars per subscription = P

Weekly bonus = Q

Minimum dollar amount to earn this week = R

Number of subscriptions sold = x

Px + Q > R

Px > R - Q

x > \dfrac{R - Q}{P}

x > X

person( 1 ) must sell at least X subscriptions this week.

10 * randRange( 300 / 10, 3000 / 10 )                    10 * randRange( 500 / 10, 1500 / 10 )                    10 * randRange( 2000 / 10, 10000 / 10 )                    ceil( (R - Q) / P )

For every level person( 1 ) completes in his( 1 ) favorite game, he( 1 ) earns P points. At the end of each hour spent playing the game, he( 1 ) earns a bonus of Q points. person(1) already has 10 * randRange( 500 / 10, 5000 / 10 ) points in the game and wants to earn more than R additional points in the next hour.

What is the minimum number of levels that person( 1 ) needs to complete in the next hour to meet his( 1 ) goal?

X levels

Points per level x Number of levels completed + Bonus points > Points goal

Points per level = P

Bonus points = X

Points goal = R

Number of levels completed = x

Px + Q > R

Px > R - Q

x > \dfrac{R - Q}{P}

x > X

person( 1 ) needs to complete at least X levels in the next hour.

randRange( 1000, 5000 )                    randRange( 10000, 25000 )                    randRange( 1, 8 )                    ceil( ( R - Q ) / X )

A bear named person( 1 ) is preparing to hibernate for the winter. He( 1 ) has already stored up Q units of energy and needs to store up at least R total units of energy before winter.

If there are X months left before winter, what is the minimum units of energy the bear needs to store up per month?

P units

Months left before winter x Units of energy stored per month + Units of energy already stored > Units of energy needed

Months left before winter = X

Units of energy already stored = Q

Units of energy needed = R

Units of energy stored per month = p

Xp + Q > R

Xp > R - Q

p > \dfrac{R - Q}{X}

p > P

person( 1 ) needs to store up at least P units of energy before the winter.

randRange( 5, 50 )                    randRange( 50, 200 )                    randRange( 1, 10 )                    ceil( ( R - Q ) / P )

To move up to the maestro level in his( 1 ) piano school, person( 1 ) needs to master at least R songs. person( 1 ) has already mastered Q songs.

If person( 1 ) can typically master P songs per month, what is the minimum number of months it will take him( 1 ) to move to the maestro level?

X months

Songs to master per month x Number of months practicing + Songs already mastered > Songs needed for maestro level

Songs to master per month = P

Songs needed for maestro level = R

Number of months practicing = x

Px + Q > R

Px > R - Q

x > \dfrac{R - Q}{P}

x > X

It will take person( 1 ) at least X months to move to the maestro level.

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