II.

10. A man $50$ years old has a son $10$ years old. In how many years will the father be three times as old as the son?

11. A has $$100$, and B has $$20$. How much must A give B in order that they may each have the same sum?

12. A banker paid $$63$ in $5$-dollar bills and $2$-dollar bills. He paid just as many $5$-dollar bills as $2$-dollar bills. How many bills of each kind did he pay?

Exercise 12.

1. In a company of $90$ persons, composed of men, women, and children, there are three times as many children as men, and twice as many women as men. How many are there of each?

2. Find the number whose double exceeds $70$ by as much as the number itself is less than $80$.

3. A farmer employed two men to build $112$ rods of wall. One of them built on the average $4$ rods a day, and the other $3$ rods a day. How many days did they work?

4. Two men travel in opposite directions, one $30$ miles a day, and the other $20$ miles a day. In how many days will they be $350$ miles apart?

5. Two men travel in the same direction, one $30$ miles a day, and the other $20$ miles a day. In how many days will they be $350$ miles apart?

6. A man bought $3$ equal lots of hay for $$408$. For the first lot he gave $$17$ a ton, for the second $$16$, for the third $$18$. How many tons did he buy in all?

7. A farmer sold a quantity of wood for $$84$, one half of it at $$3$ a cord, and the other half at $$4$ a cord. How many cords did he sell?

Let $2x$ equal the number of cords.

8. If $2x-3$ stands for $29$, for what number will $4+x$ stand?

9. At an election two opposing candidates received together $2044$ votes, and one received $104$ more votes than the other. How many votes did each candidate receive?

Exercise 13.

1. A man walks $4$ miles an hour for $x$ hours, and another man walks $3$ miles an hour for $x+2$ hours. If they each walk the same distance, how many miles does each walk?

2. A has twice as much money as B; but if A gives B $$30$, it will take twice as much as A has left to equal B's. How much money has each?

3. I have $$12.75$ in two-dollar bills and twenty-five cent pieces, and I have twice as many bills as twenty-five cent pieces. How many have I of each?