Question

Can someone help will give brainlist

Answer 1

Answer:

Option B

Step-by-step explanation:

Time taken by Nathan to completethe task = 4 hours

$\text{Work done by Nathan in 1 hour = \dfrac{x}{4} }$

Time taken by Elijah to complete the task = 3 hours

$\sf \text{Work done by Elijah in 1 hour= \dfrac{x}{3} }$

They work together to complete the work

$\text{Work done by both in 1 hour = \dfrac{x}{4}+\dfrac{x}{3} }$

                                              $\sf =\dfrac{x*3}{4*3}+\dfrac{x*4}{3*4}\\\\=\dfrac{3x}{12}+\dfrac{4x}{12}\\\\=\dfrac{7x}{12}$

$\text{Time taken by both= x \div \dfrac{7x}{12} }$

                              $\sf = x * \dfrac{12}{7x}\\\\ = \dfrac{12}{7}$

                              ≈ 1.7 hours