15. A person spent 564 in buying pens and
pencils if cost of each pen is 7 and each
pencil is 3 and if the total number of things,
bought was 108, how many of each type did he buy?
Answers
let's x be there total no. of pens and y be the total no. of pencils
7x + 3y = 564.............eq 1
x + y = 108..................eq 2
solving eq 1 and eq 2 we get
7x + 3y = 564.............eq1 x 1
7x + 7y = 756.................eq2 x 7
_____________
-4y = - 192
y = 48
from equation 2 we get
x + 48= 108
x = 108 - 48
x = 60
therefore the person both 60 pens and 48 pencils
Answer:
let's x be there total no. of pens and y be the total no. of pencils
7x + 3y = 564.............eq 1
x + y = 108..................eq 2
solving eq 1 and eq 2 we get
7x + 3y = 564.............eq1 x 1
7x + 7y = 756.................eq2 x 7
_____________
-4y = - 192
y = 48
from equation 2 we get
x + 48= 108
x = 108 - 48
x = 60
therefore the person both 60 pens and 48 pencils