75 is 25% more than () and () is 40% less than 16. If the area of a circle expands to four times of the original, its diameter (). 3 is () of 5%, 4 is 200% of (), 5 is () more than 4 and () is 25% less than 4

75 is 25% more than () and () is 40% less than 16. If the area of a circle expands to four times of the original, its diameter (). 3 is () of 5%, 4 is 200% of (), 5 is () more than 4 and () is 25% less than 4

75 is 25% more than (60) and (9.6) is 40% less than 16. If the area of a circle expands to 4 times of the original, its diameter will be 2 times of the original. 3 is (60)% of 5, 4 is 200% of (2), 5 is (25)% more than 4, and (3) is 25% less than 4

1. Both approximate number 101 and approximate number 0.101 have three significant numbers?

The approximate number 0.101 has three significant numbers that are correct
The approximate number 101 does not retain significant numbers
For example, 101.001 or 101.111 has three significant numbers
See

Liu Ming read a story book. On the first day, he read 1 / 6 of it, and on the second day, he read 42 Pages. At this time, the ratio of the pages he had read was 2:3. How many pages is the story book?

Suppose the story book has x pages
3（1/6 x+42）=2（x-1/6x-42）
x=180

If a is a root of the equation x & # 178; - 2x + 1 = 0, then the value of 2A & # 178; - 4a is

x²-2x+1=0
(x-1)^2=0
So X-1 = 0
So X1 = x2 = 1
So a = 1
So 2A ^ 2-4a = 2-4 = - 2

A person walks 5 kilometers per hour. If he takes 8 minutes less than walking for every 1 kilometer, what is the ratio between the speed of riding and walking______ ．

1 hour = 60 minutes & nbsp; 8 × 5 = 40 minutes & nbsp; 60-40 = 20 minutes & nbsp; speed of cycling: speed of walking = time of walking: time of cycling = 60:20 = 3:1

How much is the weight of 1.5mm-thick iron plate per square meter?

The volume is 0.15cm * 10000cm ^ 2 = 1500cm ^ 3
What is the density of iron
Grey cast iron 6.7.4
White cast iron 7.7.72
Malleable cast iron 7.7.43
Cast steel 7.8
Industrial pure iron 7.8759
It's usually 7.86 7.9
Assuming 7.9, the weight is 7.9 * 1500 = 11850g = 11.85kg

The bus has been running for an hour, and the car has been running for 50 minutes?

If you start at the same time and arrive at the station at the same time, it's a long way for a small car shop

Solving equations, two unknowns
First course
X=16*Y
180-X=40*(6-Y)
The second way
X*48=Y
(X+1/4)*48+(X+1/4)*40=2Y

First course
Substituting Formula 1 into formula 2
180-16y=240-40y
24y=60
y=2.5
Substituting y = 2.5 into Formula 1
x=40
The second way
Substituting Formula 1 into formula 2
88*(x+1/4)=96x
88x+22=96x
8x=22
x=2.75
Substituting x = 2.75 into Formula 1
y=132

It is known that there is no atmosphere or magnetic field on the moon, and the gravity ratio of the same object on the moon and on the earth is 1:6. The following phenomena may occur on the moon
A. Landing on the moon, the mass of the object becomes one sixth of its original mass
B. Before landing on the moon, the spacecraft can open its parachute to slow down
C. I heard the rumble of the moon after the impact
D. The soil on the moon is very soft and easy to slip when walking

Answer: D C can hear the rumble of the moon after the impact (there is no air on the moon, so the sound can't be transmitted on the surface of the moon. So it's wrong to say that standing on the moon can't hear the rumble after the impact). B spacecraft can open the parachute to slow down before landing on the moon

What is 11x + 46-4x = 100-9x-22

11x+46-4x=100-9x-22
7x+46=78-9x
7x+9x+46=78
16x=78-46
x=32/16
x=2