1)There are 2 sizes of boxes,large box and small box.The large box contain 48
chocolates while the small box can contain 30 chocolates.Now,we have 306
chocolates.Find the number of large boxes and small boxes needed to contain
all the chocolates.(The boxes should have no empty spaces after containing
2)Peter bought 72 pencil boxes.However,the receipt has been lost accidentally.He
can remember the total cost of the 72 pencil boxes is X679.Y dollars(X and Y are
the digits that he forget).Find the value of X and Y .Hence,find the selling price of
each pencil box.
3)There is a beaker of 900g sugar solution which contain 6% of pure sugar.To
increase its concentration of sugar to 10%,how many grams of water should be
- 8 年前最愛解答
1. Let there are b large boxes and s small boxes, so
48b + 30s = 308
8b + 5s = 51 ... (dividing both sides by 6)
As 16 + 35 = 51
therefore b = 2, s = 7. That is,
There are 2 large boxes and 7 small boxes.
2. As 72 = 8*9, so 79Y must be divisible by 8, ie. Y = 2.
And X6792 must be divisible by 9, so X = 3.
That is X = 3, Y = 2, the price of each pencil box is :
3679.2 / 72
= $ 51.1
3. There are 900*6% pure sugar, ie. 54g pure sugar.
In order to make the concentration to 10%, the solution must have only 540g.
900 - 540 = 360
So, 360g of water should be evaporated.