so the pattern is they add 2 then they add 4 then they add 8 then the add 16 basically they are double the number being added each number so the missing number is 14

5 0

2 years ago

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if A and B together can do a piece of work in 10 days and B along can do it in 15 days, how many part of the work does A complet

anzhelika [568]

Answer:

1/5

Step-by-step explanation:

Well work can be defined as: $work = rate \ *\ time$

where rate=amount of work that can be done in one unit of time

let a = rate of work A does in a day

let b = rate of work B does in a day

this means that: $10a + 10b=1$ where work=1 and it just means the entire job has been completed.

Since b can do it alone in 15 days, this means that: $15b=1$

If we divide by 15 here, we get the equation: $b=\frac{1}{15}$

We can now use this definition to substitute it into the first equation we made.

$10a + 10(\frac{1}{15}) = 1$

Multiply the 10 and 1/15

$10a+\frac{2}{3}=1$

subtract 2/3 from both sides

$10a=\frac{1}{3}$

Now divide both sides by 10

$a=\frac{1}{30}$

Now multiply this by 6, since we a represents the amount of work that can be done in a day, we want to find how many parts of the work can be done by a in 6 days

$6a=\frac{6}{30}$

Now divide both the numerator and denominator by 6

$a=\frac{1}{5}$

8 0

2 years ago