Birthday party

The mother bought 6 3/4 kg of hotdogs and 5 1/3 dozen bread rolls for her youngest son's birthday party. Hotdogs cost 160 per kilogram, and a dozen bread rolls cost 25. How much did she spend in all?

Correct answer:

x =  1213 ¹⁄₃ = 3640/3

Step-by-step explanation:

$$\begin{gathered} a=6\frac{3}{4}=6+\frac{3}{4}=\frac{6\cdot 4+3}{4}=\frac{24+3}{4}=\frac{27}{4}=6\frac{3}{4}=6.75 \\ b=5\frac{1}{3}=5+\frac{1}{3}=\frac{5\cdot 3+1}{3}=\frac{15+1}{3}=\frac{16}{3}=5\frac{1}{3}\doteq 5.3333 \\ x=a\cdot 160+b\cdot 25=\frac{27}{4}\cdot 160+\frac{16}{3}\cdot 25=\frac{3640}{3}=1213\frac{1}{3}=1213.3333 \end{gathered}$$

Try another example