Solution: b is regarded as a multiple of 1

Then b originally had102/(2.4+1) =102/3.4 = 30 kg.

A originally 102-30 = 72kg.

2. Two schools, A and B, donated money to the farmers who suffered from the flood. Two schools donated 3600 yuan, of which 65438+B from school A+0.5 times from school B.. How much did a school donate?

Solution: If B is regarded as a multiple of 1, then the donation from school B is 3600/(1.5+1) = 3600/2.5 =1440 yuan.

A school donated 3600- 1440=2 160 yuan.

Xiaohua brought some money to buy exercise books. I bought two books, but I still have 1.8 yuan, and I bought four books, but I still need 2.4 yuan. Solution: How much money did Hua bring?

Each book is set at one yuan.

Then 2a+ 1.8=4a-2.4.

4a-2a= 1.8+2.4

2a=4.2

a=2. 1

Each copy is 2. 1 yuan.

Use 2. 1×2+ 1.8=6 yuan.

Arithmetic: (1.8+2.4)/(4-2) = 2.1yuan.

Use 2. 1×2+ 1.8=6 yuan.

4. In order to recover funds, a store in 480 yuan sells both A and B commodities. It is known that the added goods earn 20%, and the B goods lose 20%. What is the profit and loss result of the store?

The cost price of the two commodities is

480/( 1+20%)+480/( 1-20%)

=400+600

= 1000 yuan

1000-480*2=40 yuan

Lose 40 yuan

involve

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