If 40% of a school consists of boys, 40 % of the students have blonde hair, and three times as many girls as boys have blond hair, what percentage of the school are blonde haired boys?

10% of the school are blonde haired boys.

Step-by-step explanation:

Let x be the total number of students,

Number of students who have blonde hair = 40% of the total students

= 40% of x

= 0.4x

Also, the ratio of three times as many girls as boys have blond hair,

So, the ratio of blond hair boys and blond hair girls = 1 : 3

Let the number of boys who have blonde hair = y

And, the number of girls who have blonde hair = 3y

So, y + 3y = 0.4x

4y = 0.4x ⇒ y = 0.1x

Thus, the number of boys who have blonde hair = 0.1x

Hence, the percentage of the school are blonde haired boys

=

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.

so then what are you asking?

step-by-step explanation: