There is a kind of clock that strikes at one o'clock, twice at two o'clock and three at three o'clock In addition, we have to ring every half hour. How many times did this kind of clock strike from 12:20 to 4:50 in the afternoon?

From 12:20 to 4:50 p.m., there are 4 punctual points and 5 half points, 4 punctual points: 1 + 2 + 3 + 4 = 10 (Part 2), 5 half points: 5 times, a total of 10 + 5 = 15 (Part 2). A: from 12:20 to 4:50 p.m., there are 15 times

Mathematics problems need to be calculated in detail. It's urgent today
A group of goods were delivered to teams a and B by five to three. The first team shipped 450 tons, finished 3/4 of the team's task, and transferred the remaining ones by the second team.

Team a's task accounts for 5 / 8 of the total task, and team B's task accounts for 3 / 8 of the total task
Task of team a = 450 △ 3 / 4 = 600 (tons)
Total task = 600 △ 5 / 8 = 960 (tons)
Team B carries the remaining quarter of team a and three eights of team B
600 × 1 / 4 + 960 × 3 / 8 = 150 + 360 = 510 (ton)

calculation,
Calculation: (√ 3 + 2) & # 178; - 2 (√ 3-1) (√ 3 + 1)

（√3＋2）²-2（√3-1）（√3＋1）
=3+4√2+4-2(3-1)
=7+4√2-4
=3+4√2

Find the value of X
2^4·4^4·(-0.125)^4

(2*4*0.125)^4=1

Ask a mathematical problem, (x * 0.1 + x) * 0.15 + (x * 0.1 + x) = 1000 to find the value of X. can this be calculated?

（X*0.1+X)*0.15+(X*0.1+X)=1000
1.1x*0.15+1.1x=1000
1.265x=1000
x=790.5

Define a new operation. A ⁃ B = ab-3 (a + b). If you know 5 ⁃ B (x ⁃ 7) = 7, try to find the value of X. if you make a mistake, do it according to your method

5※（X※7）=7
5※[7x-3(x+7)]=7
5※(4x-21)=7
5(4x-21)-3(5+4x-21)=7
20x-105-15-12x+63-7=0
8x=64
x=8

Guess numbers, math problems... Help... Quick········
I don't have any zeros, but when I add one, there are three zeros at the end

999
Because 999 + 1 = 1000

How much is 777 × 6 + 111 × 58? How to calculate skillfully? How to revise the math test questions of grade four

777×6+111×58
=111×7×6+111×58
=111×（7×6+58）
=111×（42+58）
=111×100
=11100

I forgot how to do it. Rational number to bracket calculation. 26.5 + (34.2-65.4 + 73.5) - 58.6
598-（-269+119-402）
6/17+（2-6/7+2/3）
7/18-（-3/7+0.6-1）
2+（1+5/2-3/1）
2/1-（-2+2/5）
calculation
-|-4/31|+（+2/7）
|-5/4|+(+2/1)
-|-14|+|-12|
|-（-7/22）|+|-21/8|
The temperature in the morning was - 9 ℃, which rose by 12 ℃ at noon and dropped by 7 ℃ in the middle of the night. What was the temperature in the middle of the night?
A water conservancy survey team walked 2 / 11 km upstream on the first day, 3 / 16 km upstream on the second day, 3 / 14 km downstream on the third day, and 2 / 11 km downstream on the fourth day. How many kilometers is the survey team away from the starting point? Is it upstream or downstream of the starting point?

26.5 + (34.2-65.4 + 73.5) - 58.6 = (26.5 + 34.2 + 73.5) + (- 65.4-58.6) = 134.2-124 = 10.2598 - (- 269 + 119-402) = 598 + 269-119 + 402 = 1269-119 = 11506 / 7 + (2-6 / 7 + 2 / 3)

The sixth grade first semester mathematics takes off the formula computation to raise 58, who can sue me? Urgently needs

1.3/7 × 49/9 - 4/3 2.8/9 × 15/36 + 1/27 3.12× 5/6 – 2/9 ×3 4.8× 5/4 + 1/4 5.6÷ 3/8 – 3/8 ÷6 6.4/7 × 5/9 + 3/7 × 5/9 7.5/2 -（ 3/2 + 4/5 ） 8.7/8 + （ 1/8 + 1/9 ） 9.9 × 5/6 + 5/6 10.3/4 ×...

There is a kind of clock that strikes at one o'clock, twice at two o'clock and three at three o'clock In addition, we have to ring every half hour. How many times did this kind of clock strike from 12:20 to 4:50 in the afternoon?