Solve:

$6.8+3.9$

Simplify: 25.67 + 9.208 + 152.1 + 63.2 

(A) 248.718 

(B) 250.718 

(C) 248.178 

(D) 250.178 

What is the value of ${\left(.4\right)}^2+{\left(.04\right)}^2+{\left(.004\right)}^2 ?$

Evaluate the following:

$234.432+507.834-178.344$

Add the following:

$1,234.432 + 567.834 + 78.342$

Dinesh went from place $\mathrm{A}$ to place $\mathrm{B}$ and from there to place $\mathrm{C}$. $\mathrm{A}$ is $7.5 \mathrm{km}$ from $\mathrm{B}$ and $\mathrm{B}$ is $12.7 \mathrm{km}$ from $\mathrm{C}$. Ayub went from place $\mathrm{A}$ to place $\mathrm{D}$ and from there to place $\mathrm{C}$. $\mathrm{D}$ is $9.3 \mathrm{km}$ from $\mathrm{A}$ and $\mathrm{C}$ is $11.8 \mathrm{km}$ from $\mathrm{D}$. Who travelled more and by how much?