Question

Roni and Allie are mowing the grass at the soccer field. Roni has a riding lawn mower and can mow the field in 30 minutes. Allie is pushing a lawn mower and can mow the field in 75 minutes.
If Roni and Allie work together to mow the field, what part of the field would Roni mow?
A. about 0.52 of the field
B. about 0.64 of the field
C. about 0.71 of the field
D. about 0.87 of the field

Answer 1

Roni would mow about 0.71 of the field.

Answer 2

Answer: C. about 0.71 of the field

Step-by-step explanation:

Since,  Roni can mow the field in 30 minutes.

Thus, the work done by Roni in one day = 1/30

And,  Allie can mow the field in 75 minutes.

Thus, the work done by Allie in one day = 1/75

⇒ The total work done by Roni and Allie in one day when they worked simultaneously,

= $\frac{1}{30} + \frac{1}{75}$

= $\frac{5}{150} + \frac{2}{150}$

= $\frac{7}{150}$

$\implies \text{The part of work done by Roni} = \frac{\text{the work done by her in one day}}{\text{Total work they done in one day}}$

$= \frac{1/30}{7/150}$

$= \frac{5}{7}=0.714285714\approx 0.71$

⇒ Option C is correct.