Answer: it will take Tammy 3 hours to do the job. Option A
Step-by-step explanation:
Let x be rate at which Laura will do the work.
Let x + 2 be rate for Jeri
Let 2 /(x + 2)be rate for Tammy
Rate of Job to be done = 1 -(1/3)÷2 = 3/4
Adding the rates together:
1/ x + (1/x+2) + 2/(x+2) = 3/4
Multiply both sides by 4x(x+2)
4(x+2) + 4x+ 8x = 3x(x + 2)
16x + 8 = 3x^2 +6x
3x^2 - 10x - 8= 0
Solving the quadratic equation you get:
3x(x-4) + 2(x -4)= 0
X=4
1. It will take Laura x= 4hrs to do the job
2. It will take Jeri x+2= 6 hrs to do the job
3. It will take Tammy 2/(x+2)= 3 hrs to do the job
