Question

The cost of some items are shown by the two functions:


Find the total cost for 10 items for both the function and choose the function name which gives an overall lower cost for 25 items.

• A. None
• B. Function B
• C. Function A
• D. Both are equal

Answer 1

The correct option is B Function B

For Function A:
Equation is y = 12.5x + 8

For 25 items, value of x = 25

$\text{∴ So, value of y =}12.5\times 25+8=\$320.5$

Cost of 25 items as per Function A = $320.5


For Function B:

$\text{Cost for 1 item =}\$10$

$\text{Additional charge =}\$3.5$

If you need to buy 25 items, then the total cost will be:

$\text{Total cost of 25 items}=25\times \$10+3.5=\$253.5$

Therefore, function B gives overall lower cost for 25 items.