88-85.5=2.5 (points) Boys' scores are 2.5 points less than the overall average.
9 1-88=3 (points) Girls scored 3 points more than the overall average.
3÷2.5= 1.2
1: 1.2 = 5: 6 ratio of boys to girls.
It takes five hours for a car to travel between Station A and bilibili. When the car went, it was 45 kilometers per hour and when it came back, it was 30 kilometers per hour. How many kilometers is the distance between Station A and bilibili?
1÷45= 1/45 (hours/kilometers) Time spent per kilometer.
1÷30= 1/30 (hour/kilometer) cycle time per kilometer.
The whole journey is 5÷( 1/45+ 1/30)=90 (km).
Two production teams, A and B, should pack the same amount of candy. Group A is hand-packed, with 5 boxes per hour; Group B is mechanically packed every hour 15 cases. It is known that group A started work 3 hours earlier than group B and finished work 3 hours later. How many boxes of candy did Group B pack?
5×(3+3)=30 (boxes) What Group A did at the beginning and the end.
15-5= 10 (box) Group B does more work every hour than Group A.
30÷ 10=3 (hours) Working hours of Group B.
15×3=45 (boxes) Group B * * * contains 45 boxes.
Two candles with different compositions but the same length, one of which needs to burn at a constant speed for 3 hours, and the other can burn for 4 hours. If the length ratio of two candles is required to be 1: 2 times 5 pm sharp, when should these two candles be lit?
The speed of the first branch is: 1÷3= 1/3 (
Party A, Party B, Party C and Party D have cooperated with a number of parts. The number of parts made by Party A is 1:2 compared with the total workload of the other three people, and the number of parts made by Party B is 1:3. The number of parts made by Party C is 25% of the total workload of the other three people, and Party D has made 520 pieces ... How many parts have four people made?
A accounts for1(1+2) =1/3 of the total number of four people.
Party B accounts for1(1+3) =1/4 of the total number of four people.
Party C accounts for1(1+4) =1/5 of the total number of four people.
Of the total number of Ding Zhan,1-1/3-1/4-1/5 =13/60.
Total amount: 520 ÷ 13/60=2400 (pieces)