One pipe can fill a tank with oil in 3 hours. A second smaller pipe can fill the same tank in 7 hours. If both pipes were used at the same time, how long would they take to fill the tank?

2.1 hours.

Step-by-step explanation:

Given , Time taken by the first pipe to fill  a tank = 3 hours

Time taken by the second pipe to fill the tank = 7 hours

If both pipes were used at the same time,  then the time taken (t) by both of them to fill the tank ( together) will be :-

Therefore, time taken to fill the tank = 2.1 hours.

the 2 figures are congruent bc if you reflect abcd over the y axis then over the d axis the figures overlap

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have