Jumped x times five minutes after setting.
1/2x+x=84
x+2x= 168
3x= 168
x=56
Method 2: You can also imagine that the jump in the last five minutes is twice that in the first five minutes.
Solution: Suppose X jumps in the first five minutes.
x+2x=84
3x=84
x=28
2. Sixth-grade students in Hongxing Primary School 180, of which the number of girls is 4/5 of that of boys. How many boys and girls are there in the sixth grade of Hongxing Primary School?
There are x boys in the sixth grade of Hongxing Primary School.
x+4/5x= 180
9/5x= 180
x= 100
This shop bought 480 baskets of apples and pears, seven fifths of which were apples. How many baskets of apples and pears did you bring in?
Suppose there are x baskets of pears brought in.
x+5/7x=480
12x/7=480
x=280
480-280=200
There are 200 baskets of apples and 280 baskets of pears.
4.20 13 years, the days with good air quality in our city are 3/2 of those with other quality. How many days is the air quality excellent? Can you solve this problem in different ways?
Other quality days are x days.
x+2/3=365
5/3x=365
x=2 19
365-2 19= 146
Days with good air quality 146 days.
5. Weight of a pile of coal 12t. The rest is 1, one-third of the shipment. How many tons have this pile of coal been carried away, and how many tons are left?
Suppose this pile of coal transported x tons.
x+ 1/3x= 12
4/3x= 12
x=9
This pile of coal has been transported away by 9 tons, leaving 3 tons.
In April of 6.20 14, there were three kinds of weather in a certain area: sunny, cloudy and rainy. Rainy days were 1 and cloudy days were 2/3 of sunny days. How many days are there in April in this area, sunny, cloudy and rainy?