A finishes a job in 10days, B finishes in 15days. if A and B work at it together, how many days will they take to complete the job

Step-by-step explanation:

so, working together, in 1 day 1/10 + 1/15 of the work is done.

how many days (x) until we get 1/1 of the work done ?

x × (1/10 + 1/15) = 1

x × (3/30 + 2/30) = 1

x × 5/30 = 1

x×5 = 30

x = 30/5 = 6

so, together, they will finish the work in 6 days.

it would open into a square depending on the type of envelope i’m not sure about the second part

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