Let p be the prize of a pen and m the prize of a mechanical pencils. If you buy six pens and one mechanical pencil, you spend 6p+m. We know that this equals 9, because you get 1$ change from a 10$ bill.
Similarly, if you buy four pens and two mechanical pencils, you spend 4p+2m, which is 8$, because now you get a $2 change. Put these equation together in a system:
Now, if you multiply the first equation by 2, the system becomes
Subtract the second equation from the first:
Plug this value into the first equation to get
Answer:
Step-by-step explanation:
Turn 1.4 into a whole number. Which makes 1.4 to 14. We know that 3 has a decimal point at the end. So move the decimal point of 3 to the right, making it 30. Now do 30/14. You will get...
30/14 = 2.14
GG ;)
Answer:
49% of the lights are on!