Answer:
This problem is incomplete, we do not know the fraction of the students that have a dog and also have a cat. Suppose we write the problem as:
"In Mrs.Hu's classroom, 4/5 of the students have a dog as a pet. X of the students who have a dog as a pet also have cat as a pet. If there are 45 students in her class, how many have both a dog and a cat as pets?"
Where X must be a positive number smaller than one, now we can solve it:
we know that in the class we have 45 students, and 4/5 of those students have dogs, so the number of students that have a dog as a pet is:
N = 45*(4/5) = 36
And we know that X of those 36 students also have a cat, so the number of students that have a dog and a cat is:
M = 36*X
now, we do not have, suppose that the value of X is 1/2 ("1/2 of the students who have a dog also have a cat")
M = 36*(1/2) = 18
So you can replace the value of X in the equation and find the number of students that have a dog and a cat as pets.
To find the answer, you have to make a proportion. 210 out of 700, or 210/700 is equal to x/100. So, 210/700=x/100. Then to solve the proportion, you must cross multiply. 210 times 100 is 21,000. Then, you must divide 21,000 by 700, which is 30. The 30 represents 30/100, which is 30%
The answer is 30%.
Answer:
It's the second one. Press 'Ask For Help' if you need more help on problems
<u>Answer:</u>
The total number of whole cups that we can fit in the dispenser is 25
<u>Solution:</u>
It is given that the height of each cup is 20 cm.
But when we stack them one on top of the other, they only add a height of 0.8 to the stack.
The stack of cups has to be put in a dispenser of height 30 cm.
So we need o find out how many cups can fit in the dispenser.
Since the first cup is 20 cm high, the height cannot be reduced. So the space to fit in the remaining cups in the stack is only 30-20 cm as that’s the remaining space in the dispenser
So,
30 - 20 = 10 cm
To stack the other cups we have 10 cm of height remaining
As we know that addition of each adds 0.8 cm to the stack, the total number of cups that can be fit in the dispenser can be calculated by the following equation. Let the number of cups other than the first cup be denoted by ‘x’.
10 + 0.8x = 30
0.8x = 20
x = 25
The total number of cups that we can fit in dispenser is 25
