Working alone, it would take shandra 40 minutes to sand a table. to sand the same table, also working alone, it would take
kelly 1 hour. if they work together, the situation can be modeled by the following equation, where t is the time it would take to
sand the table working together.
1/40+1/60=1/t
shandra claims it will take them about 50 minutes working together, because 50 is the mean of 40 and 60. which best
describes shandra's claim?

 it will take them about 24 minutes working together

Step-by-step explanation:

1/40    +   1/60 =

6/240 +  4/240 = 10/240 = 1/24

1/24 = 1/t

Cross multiplication:

1*t = 1*24  

t= 24

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.

3 is greater then both of those numbers