A store sold 21 sweatshirts. White ones cost $10.95 and yellow ones cost $12.50. In all, $260.95 worth of sweatshirts were sold. How many of each color were sold?

The store sold 1 white sweatshirt and 20 yellow sweatshirts

Step-by-step explanation:

Step 1: Express total cost of sweatshirts

Total cost of sweatshirts can be expressed as;

Total cost = (price per white sweatshirt*number of white sweatshirts sold) + (price per yellow sweatshirt*number of yellow sweatshirt sold)

where;

Total cost=$260.95

Price per white sweatshirt=$10.95

number of white sweatshirts sold=w

Price per yellow sweatshirt=$12.50

number of yellow sweatshirt sold=y

Replacing;

260.95 = (10.95*w) + (12.5*y)

10.95 w+12.5 y=260.95 ... equation 1

Step 2: Express total number of sweat shirts sold

Total number of sweatshirts sold=number of white sweatshirts sold+number of yellow sweatshirt sold

where;

Total number of sweatshirts sold=21

number of white sweatshirts sold=w

number of yellow sweatshirt sold=y

replacing;

w+y=21 ... equation 2

Step 3: Solve simultaneously equation 1 and 2

1 (10.95 w+12.5 y=260.95) >>>10.95 w+12.5 y=260.95

-

12.5 (w+y=21) >>>12.5 w+12.5 y=262.5

(10.95 w-12.5 w) + (12.5 y-12.5 y) = 260.95-262.50

-1.55 w=-1.55

w=1.55/1.55

w=1

Replace the value of w in equation 2

w+y=21

1+y=21

y=21-1=20

The store sold 1 white sweatshirt and 20 yellow sweatshirts