Boys account for
29÷ (29+21) = 29 out of 50.
Female students account for
2 1 ÷ (29+21) = 21in 50.
2. The first-phase project of Ningqi Railway (Nanjing to Hai 'an) is 2 10 km, with a total investment of 3.29 billion yuan, of which Taizhou is 43 km long. How much does the quantity of Taizhou account for in the total project?
43/2 10 = 265438+43 in 00
3. Produce a batch of parts, ***200 pieces, which is planned to be completed in 20 days. What is the average percentage of these parts completed every day?
120 = 0 in 65438+20.
How many parts do you plan to produce every day?
200 ÷ 20 = 10 (piece)
4. Both Xiao Lei and Xiaoming have walked the same long distance. Xiao Lei spent 17 hours and Xiao Ming spent 19 minutes in 60 minutes. Who walks faster?
17 out of 60 = 17.
Because 17
So Xiao Lei soon.
5. The machinery factory produced 250 machine tools in early April, 150 in the middle and 200 in the late April. What is the percentage of the number of machine tools produced in the last ten days to the total number of machine tools produced in April?
Early accounting
250 ÷ (250+ 150+200) = 65438+5/02.
Mid-term occupation
150 ÷ (250+150+200) =1times 4.
Late occupation
200÷ (250+150+200) in 3 =1.
6. Xiaohong wants to put three identical balls into boxes A, B and C. How many different ways are there?
Because the balls are all the same, only the number of balls is considered when placing, regardless of the differences between the balls.
It can be divided into three situations:
1 box is put three times, and there are three situations.
A OOO B, no c, no
OOO A no c no
Without b, there is no a.
1 When there are two in the box, there are six situations.
AOO BO C without AOO B without C O
No, no, no, no.
Chief Operating Officer Aonuo Company Chief Operating Officer Aonuo Company
1 container 1 box, and 1 box.
Aobo company
* * * There are 3+6+ 1 = 10 different ways to play.