Respuesta :
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.
[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]