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3 years ago

The ratio of boys to students is 3 to 7. If there are 20 girls in the school, then how many boys are in the school?

Mathematics

1 answer:

qwelly [4]3 years ago

5 0

Answer:

No. of boys = 15

Step-by-step explanation:

Given that,

The ratio of boys to student is 3:7.

Number of girls in the school = 20

We need to find the number of boys in the school.

Let there are 3x boys and 7x number of students.

No. of girls = Total students - no. of boys

= 7x-3x

= 4x

ATQ,

4x = 20

x = 5

No. of boys = 3x

= 3(5)

= 15

Hence, there are 15 boys in the school.

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7nadin3 [17]

Answer:

Step-by-step explanation:

B = 377lw

I will use L for length instead of l.

B = 12,252.5 BTU

w = 5 m

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12,252.5 = 377(L)(5)

12,252.5 = 1885L

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4 0

3 years ago

3x+9<br> -------- how do I solve this?<br> 4x+12

Reptile [31]

Put common terms in evidence and simplify:

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5 0

3 years ago

Read 2 more answers

The temperature changes can be represented by the expression -0.5( 1 -2h).Chase says that the temperature change can also be rep

UNO [17]

Answer:

The expression are equivalent

Step-by-step explanation:

The question requests that we show whether the equation -0.5( 1 -2h) is equivalent to 4(2h + 2) - 7h - 8.5 or not :

Simplifying 4(2h + 2) - 7h - 8.5 ; we have ;

4(2h + 2) - 7h - 8.5

8h + 8 - 7h - 8.5

8h - 7h + 8 - 8.5

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-0.5(1 - 2h)

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3 0

3 years ago

The radius of a circle is 9 kilometers. What is the circle's area?

krek1111 [17]

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I hope it helped!!!

8 0

2 years ago

8. How many ways can a committee of 5 students be chosen from a student council of 30 students? Is the order in which the member

tankabanditka [31]

Answer: A committee of 5 students can be chosen from a student council of 30 students in 142506 ways.

No , the order in which the members of the committee are chosen is not important.

Step-by-step explanation:

Given : The total number of students in the council = 30

The number of students needed to be chosen = 5

The order in which the members of the committee are chosen does not matter.

So we Combinations (If order matters then we use permutations.)

The number of combinations of to select r things of n things = $^nC_r=\dfrac{n!}{r!(n-r)!}$

So the number of ways a committee of 5 students can be chosen from a student council of 30 students= $^{30}C_5=\dfrac{30!}{5!(30-5)!}$

$=\dfrac{30\times29\times28\times27\times26\times25!}{(120)\times25!}=142506$

Therefore , a committee of 5 students can be chosen from a student council of 30 students in 142506 ways.

4 0

3 years ago