if 6 holes drilled in 8 minutes, how many in 15 minutes?

[3rdy]

i sat a test recently and in the numerical section i came across this question

if it takes 8 minutes to drill 6 holes how many holes can be drilled in 15 minutes

what is the formula to work out this question?

thanks for any help

 

[galactus]

This is a proportion.

\(\displaystyle \L\\\frac{6}{8}=\frac{x}{15}\)

Solve for x.

 

[stapel]

If he drills six in eight minutes, then how many does he drill per minute? (Hint: Divide.)

Multiply this rate by 15 to get the number drilled in fifteen minutes. :wink:

Eliz.

 

[Loren]

if it takes 8 minutes to drill 6 holes how many holes can be drilled in 15 minutes
It takes 1 minute to drill 6/8 holes. ( who ever heard of 3/4ths of a hole?)
It takes 15 minutes to drill 15*6/8 holes.
15*6/8 = 11 1/4 holes, but, again, is there such a thing as partial hole?

Corrected.

 

[fudge456]

Wait, wait, wait....

But if you drilled 6 holes in 8 minutes, wouldn't you drill 12 holes in 16 minutes?
So, then wouldn't it be maybe....11 and a half holes? please don't laugh at this because I don't really get this.

 

[Deleted member 4993]

Re: Wait, wait, wait....

But if you drilled 6 holes in 8 minutes, wouldn't you drill 12 holes in 16 minutes?
So, then wouldn't it be maybe....11 and a half holes? please don't laugh at this because I don't really get this.

You are correct - sort of.

Loren's solution has a small typo.

The answer should have been (15 * 6/8 =)11.25 holes. If I were to give such a problem - I would expect an answer of 11 (rounded down).

 

[TchrWill]

i sat a test recently and in the numerical section i came across this question

if it takes 8 minutes to drill 6 holes how many holes can be drilled in 15 minutes

what is the formula to work out this question?

thanks for any help

Thanks Subhotosh Khan for alerting me to my obvious error. When I tranferred from my notes, I accidentally flipped the term identification.

It takes 8 minutes to drill 6 holes or 3 holes/4 min.

In 15 minutes, 15min(3/4 hole/min = 15min(3holes)/4min = 11.25 holes or 11 holes of equal depth.

 

[Deleted member 4993]

i sat a test recently and in the numerical section i came across this question

if it takes 8 minutes to drill 6 holes how many holes can be drilled in 15 minutes

what is the formula to work out this question?

thanks for any help

8 minutes to drill 6 holes or 3/4 min/hole.<------------- Incorrect - should be 4/3 min/hole

In 15 minutes, 15min/(3/4min/hole = 15min(4holes)/3min = 20 holes. <--- Incorrect

 

[mallorymal]

Cross multiply. You take 6 times 15. Then you divide that answer by 8 to get the answer.