Question

A family had dinner in a restaurant and paid 30 dollars for food. They also had to pay 9.5% on sale tax and 10% for the tip. How much did they pay for dinner? Write the answer in the form of the nearest integer $ (\text{in }\$). $

Answer 1

Hint: Calculate the total tax they had to pay and the tip they had to pay. Hence calculate the total cost of having dinner. Alternatively, you can view tip and taxes as accessories and combine them as one. Hence calculate the money spent on accessories and hence find the total amount they had to pay at the dinner.
Complete step-by-step answer:
The tax and tip are charged on the food cost and not the total cost.
If x% is charged on y, the total amount charged is $\dfrac{x}{100}\times y$
Hence we have,
Amount to be paid as taxes = 9.5% of 30 $=\dfrac{9.5}{100}\times 30=\$2.85$
Amount to be paid as tip $=\dfrac{10}{100}\times 30=\$3$
Hence the total amount to be paid $ =\$3+\$2.85+\$30=\$35.85 $
Nearest integer to 35.85 is 36
Hence they have to pay $=\$36$
Note: [1] Alternatively, we have
The % of the cost of the food they have to spend on accessories is 10+9.5 = 19.5%
Hence the amount they had to pay for dinner is $=30+\dfrac{19.5}{100}\times 30=30+5.85=\$35.85$
Nearest integer to 35.85 is 36
Hence they had to pay 36 dollars for dinner.
[2] When converting to the nearest integer if the tenths place $\ge $5, then take the next larger integer and if the tenths place is <5, then take the previous smaller integer.