Which of the following expressions could give the total amount of a $45 restaurant bill with a 15% tip added on?

1 + (0.15)($45)
(1.15)($45)
$45 + 0.15
(0.15)($45)

1 answer

To calculate the total amount of a $45 restaurant bill with a 15% tip added, you can add 15% of the bill to the original bill amount.

  1. Calculate 15% of the bill:
    \( 0.15 \times 45 = 6.75 \) (this is the tip)

  2. Add the tip to the original bill:
    \( 45 + 6.75 = 51.75 \)

Alternatively, you can factor the original bill into a single expression:

  • Total amount (including tip):
    \( 45 + (0.15 \times 45) = 45 + 6.75 = 51.75 \)
    or
    \( (1 + 0.15) \times 45 = 1.15 \times 45 = 51.75 \)

Based on the expressions you provided:

  1. \( 1 + (0.15) \times 45 \) - This gives \( 1 + 6.75 \) instead of the total bill with tip.
  2. \( (1.15) \times 45 \) - This correctly gives the total amount, which is \( 51.75 \).
  3. \( 45 + 0.15 \) - This results in \( 45 + 0.15 = 45.15 \), which is incorrect.
  4. \( (0.15) \times 45 \) - This just gives the tip amount, \( 6.75 \), not the total.

Therefore, the correct expression that gives the total amount of the $45 restaurant bill with a 15% tip added on is:

(1.15)($45)