Arabica coffee costs $28 per pound and Robusta coffee costs $8.75 per pound. How many pounds of Arabica coffee
must you mix with 3 pounds of Robusta coffee to make a
blend that costs $15.50 per pound?

1.62 pounds

Step-by-step explanation:

Let x be the pounds of Arabica

Take the number of pounds times the cost of each of the coffees individually

This must be equal to the number of pounds times the cost together

x * 28 + 8.75 *3 = ( x+3) 15.50

28x+26.25=(x+3)15.50

Distribute

28x+ 26.25 = 15.50x + 46.50

Subtract 15.50x from each side

28x-15.50x +26.25 = 15.50x +46.50-15.50x

12.50x + 26.25 = 46.50

Subtract 26.25 from each side

12.50x +26.25-26.25 = 46.50-26.25

12.50x = 20.25

Divide each side by 12.5

12.5x/12.5 = 20.25/12.5

x =1.62

answer: - (a)

(b) 88 seats

step-by-step explanation:

given: in an auditorium, there are 22 seats in the first row and 28 seats in the second row.

thus first term=

second term=

the number of seats in a row continues to increase by 6 with each additional row.

⇒d= 6

a) given formula :

b)   let the number of seats (n) = 12

substitute n=12 in the explicit rule formed in (a)

∴there are 88 seats in 12 rows.