Question

One person can do a certain job in ten minutes, and another person can do the same job in fifteen minutes. How many minutes will they take to do the job together?

Answer 1

7.5 minutes

Answer 2

that isnt one of the answers the options are
A) 4 min
b) 5 min
c) 6 min
and please show me the process

Answer 3

i apologise it is 4 minutes, i mis calculated. so if we call 10 minute man A and 15 minute man B. Lets take the job as having 15 little tasks. A does 1.5 tasks/minute B does 1 task/ minute. make sense ?

Answer 4

then together they do 2.5 tasks per minute and 15/2.5 is not 4 but 6 haha wrong twice

Answer 5

The formula for this one isn't too hard. Add the rates, keeping in mind that the rate is the reciprocal of the time. For this problem,\[\frac{1}{10}+\frac{1}{15}=\frac{1}{T}\]where T is the time working together.

Answer 6

i think the total time is 25 if everybody do the work himself
then 10/25 +15/25

Answer 7

\[\frac{1}{10}+\frac{1}{15}=\frac{1}{T} \implies \frac{5}{30}=\frac{1}{T}\implies T=6\]

Answer 8

ok that makes sense thanks

Answer 9

Keep working. Do math every day.