Answer:
The supply store sold 18 packs of pencil and 10 packs of pen
Explanation:
The supply store sells writing utensils. The cost for each pencil is $1.50 and the price for each pen is $4.
The total number of pen sold a particular day = 28
let the number of pencil sold = a
the number of pen = b
a + b = 28.................(i)
The total cost made can be computed as
1.5a + 4b = 67..........(ii)
a + b = 28.................(i)
1.5a + 4b = 67..........(ii)
a = 28 - b
insert the value of a in equation (ii)
1.5(28 - b) + 4b= 67
42 - 1.5b + 4b= 67
67 - 42 = 2.5b
dvide both sides by 2.5
b = 25/2.5
b = 10
insert the value of b in equation (i)
a + b = 28.................(i)
a = 28 - 10
a = 18
The supply store sold 18 packs of pencil and 10 packs of pen