Hi! Can someone please help me? Julie an experienced bricklayer can build a wall in 55 hours, while her daughter can do the job in 66 hours. How long will it take for them to build the wall together?

30 hrs

Step-by-step explanation:

In 1 hour, J completes 1/55 of job

In that time, D completes 1/66 of job

J + D together complete 1/55 + 1/66 of the job in 1 hour

1/55 + 1/66 = 1/30

Together, it takes them 30 hours to build the wall.

your answer would be b

step-by-step explanation:

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)