又有Maths 題啦~( 3

1. In a supermarket, the price of an apple is $2.5, and an orange is $3. Alan got $2 left afterr buying some apples. However, he would need $2 more if he wanted to buy the same number of oranges.Find the number of apples he bought.
Let the number of apples Alan bought be A.
2.5 * A + 2 = 3 * A - 2
2 + 2 = 3A - 2.5A
4 = 0.5A
8 = A
A = 8
i.e. the number of apples he bought = 8
2. A sum of money is to be evenly shared among 10 persons. However, two of them are absent, so each of the 8 attendees gets $30 more. Find the total amount of money.
Let the total amount of money be $M.
M / 10 + 30 = M / 8
M / 10 * 40 + 30 * 40 = M/8 * 40
4M + 1200 = 5M
1200 = M
M = 1200
That is, total amount of money is $1200.

1.Let x be the number of apples he bought,
2.5x+2+2 = 3x
0.5x=4
x=8
Therefore, he bought 8 apples.

2.Let X be the total amount of money,
X/8= X/10+30
X/8-X/10=30
2X/80= 30
X=1200
therefore the total amount of money is $1200.