Question

Mike can build a go cart in 30 days, Jed can build one in 20 days and Erick in 60 days. If all of them share the work, how quickly can they build a go cart?
I know the answer is 10, but how do I get to that?

Answer 1

Answer:

Together they build a cart in 10 days.

Step-by-step explanation:

Given : Mike can build a go cart in 30 days, Jed can build one in 20 days and Erick in 60 days. If all of them share the work.

To find : How quickly can they build a go cart?

Solution :

Let the work done be in x days.

and total work done is 1.

Then, Mike can build a go cart in 30 days

i.e. Mike done his work in $\frac{x}{30}$

Jed can build one in 20 days

i.e. Jed done his work in $\frac{x}{20}$

Erick can build one in 60 days

i.e. Erick done his work in $\frac{x}{60}$

If they work together work done is 1.

i.e.  $\frac{x}{30}+\frac{x}{20}+\frac{x}{60}=1$

Taking LCM,

$\frac{2x+3x+x}{60}=1$

Cross multiply,

$6x=60$

$x=\frac{60}{6}$

$x=10$

Therefore, Together they build a cart in 10 days.

Answer 2

Answer: 10 days

Step-by-step explanation:

Mike: $\frac{x}{30}$

Jed: $\frac{x}{20}$

Erick: $\frac{x}{60}$

Together: $\frac{x}{30}$ + $\frac{x}{20}$ + $\frac{x}{60}$ = 1

60$(\frac{x}{30}$ + $\frac{x}{20}$ + $\frac{x}{60}$ = 1)

2x + 3x + x = 60

             6x = 60

               x = 10