There is a four-digit number. Add a decimal point and then add it to the original number, and the total is 30 16.87. The original four digits were (2987). Because it is 30 16.87, the last two digits of the four-digit number are 87, so the first two digits are 29.
There are two numbers that have multiple relationships. Their greatest common divisor is 16 and their smallest common divisor is 96. These two numbers are (32) and (48). The greatest common divisor is 16. Hold two numbers that are multiples of 16 and factors of 96, namely 32 and 48.
The degree ratio of the three internal angles of a right triangle is 1:2: 1. If triangles are classified by sides, they are isosceles right triangles.
Because the angle ratio is 1: 2: 1 and the sum of the internal angles of the triangle is 180, the degrees of these three angles are 45, 90 and 45 respectively. Because there is a right angle and the two angles are equal, this is an isosceles right triangle.
Xiao Ming has read two-sevenths of a book and finished 80% of the whole book after reading 54 pages. How many pages are there?
This book has x pages.
2\7x+54=0.8x
18\35=54
x= 105
This book has 105 pages.
Cars A and B leave from places A and B at the same time and meet in five hours. Then they continued to drive in the same direction for three hours. At this time, there is still135km between A and B, and165km between A and B ... How many kilometers is there between A and B?
Let a and b be x kilometers apart.
Relationship: (speed A+ speed B) ×5= total distance.
[(x- 165)\ 8+(x- 135)\ 8]×5 = x
(x- 165)\8 is the speed of B, (x- 135)\8 is the speed of A, and 8 means 3+5=8 hours.
(x \ 8-20.625+x \ 8- 16.875)×5 = x
(x\4-37.5)×5=x
5x\4- 187.5=x
x\4= 187.5
x=750
A and b are 750 kilometers apart.
A pile of sand and gravel can hold 140 medium-sized trucks and 80 large trucks, and each medium-sized truck is less than the large trucks, with 1.8 tons. How many tons is this pile of sand and gravel?
If a medium-sized truck can hold x tons, a large truck can hold (x+ 1.8) tons.
140x=80(x+ 1.8)
140x=80x+ 144
60x= 144
x=2.4
So 140x=336.
This pile of sand and gravel weighs 336 tons.
After the five judges scored the players, the highest and lowest scores were removed, and the average score was 9.2. If only one highest score is removed, the average score is 8.65, and if only one lowest score is removed, the average score is 9.65. What are the highest and lowest scores of this athlete?
9.2×(5-2)=27.9(5-2) means removing the highest and lowest points.
8.65× (5-1) = 34.6 (5-1) means that the highest score is removed.
So the lowest score: 34.6-27.9=6.7.
9.65× (5-1) = 38.6 (5-1) means that the lowest score is removed.
So the highest score: 38.6-27.9= 10.7.
There are twice as many apples as oranges. Three oranges, four more, seven apples, five less. Some friends and some apples.
There are x children.
(3x+4)×2=7x-5
6x+8=7x-5
x= 13
7x-5=86。
There are 13 children and 86 apples.