If Machine A makes a yo-yo every five minutes and Machine B takes ten minutes to make a yo-yo, how many hours would it take them working together to make 20yo−yos?

If every 5 mins, A makes 1 yo-yo every 10 mins, B makes 1 yo-yo then every 10 mins, both machines produce 3 yo-yos every 10 mins (2 from machine A and 1 from machine B) Therefore, for 20 yo-yos, both machines would take 70 minutes( 1 hour and 10 mins). After 70 minutes, 21 yo-yos would be produced.

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RenatoMattice RenatoMattice · Answer 2 · 2018-11-13T08:24:09+01:00

[tex]\text{Answer: They need }1\frac{1}{9}\text{ hours working together to make 20 yo yos}[/tex]

Explanation:

Since we have given that

Time taken by Machine A to make a yo- yo = 5 minutes

Work done by Machine A in 1 minute is given by

[tex]\frac{1}{5}[/tex]

Time taken by Machine B to make a yo - yo = 10 minutes

Work done by Machine B in 1 minute is given by

[tex]\frac{1}{10}[/tex]

Work done by both of them altogether is given by

[tex]\frac{1}{5}+\frac{1}{10}=\frac{2+1}{10}=\frac{3}{10}[/tex]

Now, he can do,

[tex]\frac{3}{10}\text{ work in 1 hour by both of them }[/tex]

We need to find the number of hours working together to make 20 yo-yos,

[tex]\frac{10}{3}\times 20=\frac{200}{3}\ minutes=\frac{200}{3\times 60}\ hours=\frac{10}{9}\ hours=1\frac{1}{9}\ hours[/tex]

Hence,

[tex]\text{ They need }1\frac{1}{9}\text{ hours working together to make 20 yo yos}[/tex]