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Shek Yin 發問於 科學及數學數學 · 10 年前

# Inequalities in One Unknown

The weight of Mary is x kg.John is 10kg heavier than Mary while Yvonne is 5kg lighter than Mary.

(a) Express the weight of John and Yvonne in terms of x

(b) Mary,,john and Yvonne are going to enter a lift in which there are 4 people of weights 36 kg,42kg,53kg and 73kg respectively.Suppose the maximum load of the lift is 350kg,find the maximum weight of Mary such that the lift will not be overloaded.

### 1 個解答

• 10 年前
最愛解答

(a)

The weight of John is (x+10)kg and Yvonne is (x-5)kg

(b)

(The weight of Mary,John,Yvonne and the others should not greater than 350kg )

So,

x+(x+10)+(x-5)+36+42+53+73<=350

x+x+10+x-5+36+42+53+73<=350

3x<=141

x<=47

Therefore, the maximum weight of Mary is 47kg so that the lift will not be overloaded..

Hope I can help you :)