1. Calculate the following problem. Three fifths times 20 = 12 Seven fifths 1=22/2 1.

0 of 65438+7 times 2/3 = 2/22.

2/9 times 18 = 4/4 minus 8/6 1 = 5/8 2/9 times 4=8/9 15 times 5/8.

4/5 times1=110 2. Among invertebrates, squid swims fastest, with a speed of 65438+9KM/ min. How many kilometers can it swim in 30 minutes? 1 hour?

Solution: 9/ 10 times 30=27Km.

1h = 60 minutes

9/ 10 times 60 = 54 km

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8. A beverage factory allows users to use an automatic detector to detect whether a beverage bottle is defective, and the time for detecting a bottle is 1/25 seconds. /kloc-how many bottles can be detected per minute?

Solution: 60/( 1/25)= 1500.

9. The movie pictures we usually see are actually played by many continuous photos at the speed of 1/24 seconds each. How many photos can you put in half a second? 1 min?

Solution: (1/2)/(1/24) =12 sheets.

1 min =60 seconds

60/( 1/24)= 1440 sheets

There is no practice on page 28. I wrote 33 pages. I have been typing for a long time. Hope to be rewarded!