Y=42 Y=?
X=6 X=3
cross multiply
so 42times3=6timesY
126=6Y
Y=126 divided by 6
=21
If Simone has 20 bills, then:
1/5 of 20 = 4 [hundreds]
1/4 of 20 = 5 [fifites]
1/10 of 20 = 2 [$20s]
4 * 100 + 5 * 50 + 2 * 20 = 400 + 250 + 40 = 690 [out of $780]
4 + 5 + 2 = 11 [out of 20 bills]
So now we can easily find out she had 9 bills of tens - because 20 - 11 = 9 or because (780 - 690) ÷ 10 = 90 ÷ 10 = 9.
It took 3 days to complete a work by 10 people.
<h3>What is Efficiency?</h3>
The efficiency is the output of the work which we divide by the work input and then express it in a percentage form.
Here, Efficiency of 1 person to complete a piece of work in 30 days is 1/30.
The number of days to complete the work = n days
Number of person to complete the work = p.
Now, according to question
Number of days to complete the work by 10 people = 30 / 10
= 3 days.
Thus, it took 3 days to complete a work by 10 people.
Learn more about Efficiency from:
brainly.com/question/13828557
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Answer:
area of rectangle=l×b=2.4×5.8=13.92cm²