An office supply store has five different packages of black ink pens which is the best deal available on black ink pens at this office supply

12 pack for $15.00

Step-by-step explanation:

4 pack for $7.00:  7 ÷4  = 1.75

6 pack for $10.25:  10.25 ÷6 ≈ 1.71

10 pack for $13.00:  13 ÷10  = 1.30

12 pack for $15.00:  15.00 ÷12 = 1.25

25 pack for $32.50:  32.50 ÷25 = 1.30

idk

step-by-step explanation:

idk

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5