Question

Lesson 5.3: Rational

Answer 1

Answer:

It will take 18 minutes to fill the trough using both pumps.

Step-by-step explanation:

Given that:

Time taken by pump A = half hour = 30 minutes

Time taken by pump B = three quarters of an hour

One quarter = $\frac{1}{4}$

One hour = 60 minutes

Three quarters of an hour = $\frac{3}{4}*60$ = 45 minutes

Let,

x be the time taken by both pumps to fill the trough.

$\frac{1}{time\ taken\ by\ pump\ A}+\frac{1}{time\ taken\ by\ pump\ B}=\frac{1}{Time\ taken\ by\ both\ pumps}$

$\frac{1}{30}+\frac{1}{45}=\frac{1}{x}\\\\\frac{3+2}{90}=\frac{1}{x}\\\\\frac{5}{90}=\frac{1}{x}\\\\\frac{1}{18}=\frac{1}{x}\\x=18$

Hence,

It will take 18 minutes to fill the trough using both pumps.