number of markers ..... 35 , so 7 packs
number of erasers ...... x
number of whiteboards .... y
cost of markers ------ $6 per pack
cost of erasers ------ $2
cost of whiteboards ---- $10
x+y+35 = 56
x + y = 21 **
7(6) + 2x + 10y = 140
2x + 10y = 98
x + 5y = 49 ***
subtract ** from ***
4y = 28
y = 7
carry on .....
Pete recently bought whiteboard supplies for employees in his office. He spent $140 on whiteboards, markers, and erasers. The markers came in packs of 5, which cost $6 per pack. One (1) eraser was 1/3 of the cost of 1 pack of markers and 1 whiteboard was 5 times the cost of 1 eraser. If Pete purchased 56 items in total, including 35 markers, then how many whiteboards did he buy?
1 answer