There are three people in the family. My father is three years older than my mother. Now the total age of the family is 80 years old. Ten years ago, the total age of the whole family was 51 years old. My daughter is now 80 years old______ I'm 40 years old

3 × 10 = 30 (years old) & nbsp; 80-51 = 29 (years old) & nbsp; & nbsp; 30-29 = 1 (years old) so ten years ago, my daughter was not born, nine years ago, so I am nine years old

Xiao Ming is 26 years younger than his mother, and his father is 4 years older than his mother. The sum of their ages is 77. How old is Xiao Ming this year?

Xiaoming is 26 years younger than his mother, which means that his mother was 26 years old. At that time, Xiaoming's father was 30 years old. At this time, the total age of the three students is 26 + 30 + 0 = 56. It's 21 years away from 77, because each of the three people

Jingjing did 7 math problems in 12 minutes and Yingying did 5 math problems in 8 minutes. Which of them can do faster?

Time of Jingjing: 12 / 7 = 60 / 35
Time of a question: 8 / 5 = 56 / 35
Yingying uses less time, so Yingying is fast
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Jingjing did 7 math problems in 12 minutes and Yingying did 5 math problems in 8 minutes. Which one of them did it faster

Jingjing does seven out of twelve questions, Yingying does five out of eight questions, because after seven out of twelve, it is 14 out of 24, after five out of eight, it is 15 out of 24, so five out of eight is greater than seven out of twelve, Yingying does it faster

A math problem: in 2009, my grandfather's age is 10 times that of my grandson. In another 12 years, my grandfather's age is 4 times that of my grandson. How old is my grandson in 2010

In another 12 years, the grandson's age will increase by 12 years
If grandfather's age increases by 12 × 10, he will be 120 years old
So grandfather is 10 times as old as grandson
Now my grandfather is only 12 years old, and his age is four times that of his grandson
12 years later, the grandson's age is: (120-12) / (10-4) = 18 years old
This year, grandson: 18-12 = 6 years old
In 2010, grandson: 6 + 1 = 7 years old

Fourth grade math problem Jingjing walks to school in the morning, 60 meters per minute, 5 minutes late, 75 meters per minute, 2 minutes in advance, Jingjing's home to school
Jingjing home to the school journey, to use fourth grade addition, subtraction, multiplication and division operation, please tell me the solution, thank you

Analysis: 1. Distance = speed * time = distance / speed speed = distance / time
2. If you find the specified time, it's easy to find it
3. Calculation method of specified time: within specified time
After every minute, walk 15 meters more. Walk 60 * 5 + 75 * 2 = 450 meters more, and the specified time is 450 / 15 = 30 minutes
Solution: 60 * [(6085 + 75 * 2) / (75-60)] + 60 * 5 = 60 * 30 + 60 * 5 = 2100m
Or 75 * [(6085 + 75 * 2) / (75-60)] - 75 * 2 = 75 * 30-75 * 2 = 2100m
A: 2100 meters

Huanhuan had a fever. Her mother took her to see a doctor. As a result, her temperature was 39.2 ℃
2 ℃, and the temperature of Huanhuan after two hours

The temperature of 37.6 ℃ returned to normal

Ten years ago, the father's age was seven times that of his daughter. 15 years later, the father's age is two times that of his daughter. Q: is the father () now?

Ten years ago, the father's age was seven times that of his daughter. 15 years later, the father's age is two times that of his daughter. Q: is the father (45) years old now?
Ten years ago, if the age of the daughter was x, the age of the father was 7x
[7X+10+15]=[X+10+15]*2
X=5
The father is now: 7 * 5 + 10 = 45

Ten years ago, the father's age was seven times that of his daughter. 15 years later, the father's age is twice that of his daughter. What's the father's age?

She is y-year-old father and x-year-old daughter
(Y-10)/(X-10)=7
(Y+15)/(x+15)=2
Solving the equation, y = 45, x = 15

This year, the age of father is four times that of daughter. Three years ago, the sum of the ages of father and daughter was 49. How old is father and daughter?

Three years ago, the age sum of father and daughter was 49, and three years later, it was 49 + 3 + 3 = 55
Let's set their age this year as X and 4x respectively
Then x + 4x = 5x 5x = 55
So x = 11 4x = 44
So this year, the father is 44 and the daughter is 11
Three years ago, my father was 41 and my daughter was 8

There are three people in the family. My father is three years older than my mother. Now the total age of the family is 80 years old. Ten years ago, the total age of the whole family was 51 years old. My daughter is now 80 years old______ I'm 40 years old