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maths question help limits of accuracy watch

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    I have this question in my homework and i cannot work out what I am missing, any help would be fabulous! thanks

    Distance = 187km to 3sf
    petrol = 28l to 2sf
    consumption is c = d divided by p.
    consider bounds of accuracy to work out c.

    I have answered:
    187km ± 0.5 = 187.5km or 186.5km
    upper bound of distance 187.5km
    28l ±0.5 = 27.5l or 28.5l
    upper bound of fuel consuption 28.5litres
    Upper bound km ÷ upper bound fuel used
    187.5 ÷ 28.5 = 6.579km/l
    therfore 6.579km/l = 187.5km ÷ 28.5l

    what am I missing??

    thank you !
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    (Original post by autobotjtb)
    I have this question in my homework and i cannot work out what I am missing, any help would be fabulous! thanks

    Distance = 187km to 3sf
    petrol = 28l to 2sf
    consumption is c = d divided by p.
    consider bounds of accuracy to work out c.

    I have answered:
    187km ± 0.5 = 187.5km or 186.5km
    upper bound of distance 187.5km
    28l ±0.5 = 27.5l or 28.5l
    upper bound of fuel consuption 28.5litres
    Upper bound km ÷ upper bound fuel used
    187.5 ÷ 28.5 = 6.579km/l
    therfore 6.579km/l = 187.5km ÷ 28.5l

    what am I missing??

    thank you !
    Are you working out the best possible fuel consumption? If so I would be using the upper bound for distance (max distance) and the lower bound for fuel (least fuel), so 187.5/27.5.

    The worst possible fuel consumption would be lower bound for distance/upper bound for fuel.
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    Thanks! I will give that a try
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    Max C is where D is max and P is min
    Min C is where D is min and P is max

    Think about eating a slice of pie, if u have a large piece and eat a small amount ( u have a max amoun left) vice versa
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Updated: February 13, 2018
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