Multiplying ratios is just like multiplying fractions.

Ex:

5:10 = 5/10

5:10 · 2:20 = 5/10·2/20.

keep 5/10,
simplify 2/20 to 1/10,
multiply 5·1, and 10·10, and the answer is 5/100 or .05

8 0

3 years ago

Computer a can carry out an engineering analysis in 6 hours, but computer b can do the same job in 4 hours. how long does it tak

erik [133]

Computer A can carry out analysis in 6 hours. That means in an hour, computer A does $\frac{1}{6}$ of the job.

Computer B can carry out analysis in 4 hours. That means in an hour, computer B does $\frac{1}{4}$ of the job.

If both computers work together, in an hour they do:
$\dfrac{1}{6}+ \dfrac{1}{4}$
$= \dfrac{2}{12}+ \dfrac{3}{12} \text{(equalize the denominators)}$
$= \dfrac{5}{12}$
In an hour, they do $\frac{5}{12}$ of the job.

To finish the job, they need $\frac{12}{5}$ hours.
$\dfrac{12}{5}$ hours
= 2.4 hours
= 2 hours + 0.4 hour
= 2 hours + 0.4 × 60 minutes
= 2 hours 24 minutes

They finish analysing in 2 hours 24 minutes

6 0

3 years ago