Xiaofang spent three minutes doing 48 mental arithmetic problems and made five mistakes. Xiaoli spent five minutes doing 70 mental arithmetic problems and made nine mistakes. Whose mental arithmetic accuracy is higher

Xiaofang spent three minutes doing 48 mental arithmetic problems and made five mistakes. Xiaoli spent five minutes doing 70 mental arithmetic problems and made nine mistakes. Whose mental arithmetic accuracy is higher

The correct rates are (48-5) / 48 = 0.895833, (70-9) / 70 = 0-871429
So Xiaofang's accuracy is higher

Among the following objects, the nearest 1kg is a. an orange B. an egg c. a bottle of water D. a brick

The analysis is as follows
Option a, an orange, who has bought oranges all know that, generally, there are about 3-7 oranges per kilo (500g), then its mass is generally between 150-350g;
Option B, an egg, a catty of eggs generally have 8-11, then its quality is generally between 45-65g;
Option C, a bottle of water, here should refer to mineral water, its volume is 500-650ml, that is, 500-650g, plus the mass of the bottle, that is, about 700g
Option D: a brick weighs more than a bottle, about 1250g, so it's closest to 1kg
To sum up, D should be chosen

Give you a scale, a watch, a bicycle, what physical quantities can you measure with them

Time, distance, speed
Time: look at your watch
Distance. Measure the circle diameter, calculate the diameter, count the number of turns, and finally get the distance,
Speed, divide distance by time

A bicycle factory plans to produce 250 bicycles a day this week. The comparison between the actual daily output and the planned output is shown in the table below
Increase the number of vehicles recorded as a positive number, decrease the number of vehicles recorded as a negative number) Monday 23456 increase and decrease the number of vehicles - 5. + 7. - 3. + 4. + 10. - 9.25 Sunday production compared with the plan, this week's total output increase and decrease the number of this week's most production day, less than the production day. 2!
-5.+7.-3.+4.+10.-9.-25

250 + (- 25) = 250-25 = 225 (vehicles) Sunday production (225) - 5 + (+ 7) + (- 3) + (+ 4) + (+ 10) + (- 9) + (- 25) = - 5 + 7-3 + 4 + 10-9-25 = (7 + 4 + 10) - (5 + 3 + 9 + 25) = 21-42 = - (42-21) = - 21 (vehicles) this week's output increase or decrease is (- 21) + 10 - (- 25) = 10 + 25 = 35 (vehicles)

How to set the bicycle speedometer
For example, after the battery is installed on the watch, there will be four numerical jumps. The initial value is 2060. I want to know how to set it according to the circumference of the bicycle wheel. What's the radius of the induction head installed on the spoke? Specifically, I use it on a small wheel with a circumference of 25 to 30cm to find out the setting on the watch and the installation radius of the magnetic head. I want to know more from you~

The position of 2155 induction head should be combined with the signal input part, generally no more than 5mm

The gravity of the following objects is about 50 N. This is a science textbook B an egg C a chicken d a middle school student

G = mg. (gravity = mass * gravity constant)
G = 9.8n/kg (9.8N for an object with a mass of 1kg)
In calculation, G is usually regarded as 10N / kg
So 50N is about 5kg
So the answer is C

The weight of an egg is about
A0.5N
B5N
C0.5KG
D50N

50g
That's 0.5N

What is the approximate gravity of an egg?
The unit is n

0.5N

The gravity of two eggs is 1 Niu, and the gravity ratio of two eggs to a middle school student's human body is 1:490, then how many kg is the mass of a middle school student's human body

The gravity of the human body is 490N
The mass of human body is m = g / g = 490N / 9.8n/kg = 50kg

A plus a minus power equals 7, a square - a minus square equals?

A + 1 / a = 7: a + 2 + 1 / a = 49, a + 1 / a = 47 (A-1 / a) = A-2 + 1 / a = (a + 1 / a) - 2 = 47-2 = 45 A-1 / a = 3 √ 5 A-1 / a = (a + 1 / a) (A-1 / a) = 7 × 3 √ 5 = 21 √ 5