Question 924418
Andy and Violet are planting trees.
 Andy can plant a tree 1.25 times as quickly as Violet can.
 When they work together, they can plant 25 trees in an hour and 10 minutes.
 How long would it take Violet to plant the 25 trees if she were working alone?
:
Change 1 hr 10 min to 1.167 hrs
:
let t = time required by A to plant 25 trees
then
1.25t = time required by V to plant 25 trees
:
let the completed job = 1 (the planting of 25 trees)
:
A shared work equation
{{{1.167/t}}} + {{{1.167/(1.25t)}}} = 1
multiply equation by 5t, get rid of the denominators
5(1.167) + 4(1.167) = 5t
5.835 + 4.668 = 5t
10.5 = 5t
t = 10.5/5
t = 2.1 hrs A working alone
then
1.25 * 2.1 = 2.625 hrs V working alone, that's 2 hr + .625(60) = 2 hrs 37.5 min
:
:
See if that checks out
{{{1.167/2.1}}} + {{{1.167/(2.625)}}} ~ 1