(It might also have helped immensely if you had been listening
when this was being explained in class.)

The first pipe fills 1/20 of the tank each minute.
The second pipe fills 1/30 of the tank each minute.

Operating together, the two pipes fill ( 1/20 + 1/30 ) of the tank each minute.

In order to add these fractions (or any fractions), you need a common denominator.
For these particular ones, ' 60 ' is a good choice.

( 1/20 + 1/30 ) = ( 3/60 + 2/60) = 5/60 = 1/12

The rate of work is 1/12 tankful per minute .

The most sensible choice for the time is 12 minutes.

R x T = W

( 1/12 tankful per minute ) x ( 12 minutes ) = 1 full tank

8 0

3 years ago

Triangle DBC is equilateral,<br>AB = AC. Work out the size of angle x. <br><br><br>Pls asap

allochka39001 [22]

Answer:

x = 21º

Step-by-step explanation:

∆ ABC is isosceles therefor

Angles B and C are congruent

(180 - 18)/2 = 162/2 = 81º

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∆ BCD is equilateral therefor all angles are 60º

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x = = 81 - 60

x = 21º

3 0

3 years ago