45% of 40 is 0.45×40=18 girls
if x girls join then 56% of 40+x is 0.56(40+x)=18+x
22.4+0.56x=18+x
put together like terms
4.4=0.44x
x=10 girls joined
Answer:
Step-by-step explanation:
Emily's unit rate in miles per hour can be found by using the expression 9 ÷ (3/4) or 9 x (4/3). When calculated, we find that Emily is biking at a rate of 12 miles per hour.
To find Emily's unit rate in miles per hour, we need to divide the total miles she biked by the time it took her in hours. In Emily's case, she biked 9 miles in 3/4 hours. So the expression she can use to find her unit rate in miles per hour is 9 ÷ (3/4). Dividing 9 by 3/4 is the same as multiplying 9 by the reciprocal of 3/4, which is 4/3. So, the expression can also be written as 9 x (4/3). If we calculate that, we get 12. So, Emily biked at a rate of 12 miles per hour.
#SPJ2
Answer:
Hello there!
Divide 9 by 3 to get 3.
Then use that to multiply 3 by 4 to get 12.
Step-by-step explanation:
G. 0−8
H. 0 8
J. 19
K. 20
They were one-third of the way across the bridge, when the sound of a train whistle brought them instantly back to reality. Looking back over their shoulders, they saw a huge locomotive pulling tons of boxcars coming directly at them at 24 miles per hour! Using all their powers of mathematical reasoning, Pooters and Dooters immediately figured that they could run directly ahead and get to the far edge of the bridge at the exact same instant as the train. But they also knew that they could run back toward the train and get to the near end of the bridge just as the train got there. Basically, they knew they were dead meat.
How fast do Pooters and Dooters run?
please help me get an equation to solve the problem.