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 earned 20%, and the goods B lost 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
At the same time, two trains depart from Party A and Party B relatively. The speed of the express train is150km, and the speed of the local train is 90km. They meet at a distance of 240 kilometers from the midpoint. How many kilometers is it between Party A and Party B?
Solution: the express train runs more than the local train 150-90=60 km/h.
Then the express train is 240×2=480 kilometers longer than the local train.
Meeting time =480/60=8 hours
Distance between Party A and Party B = (150+90) × 8 =1920km.