-- 30 miles per hour

-- $6.50 per hour

-- 365 days per year

-- 60 seconds per minute

-- $2.49 per pound

-- 3.47⁹ per gallon

-- 1800 calories per day

-- 360 degrees per revolution

7 0

3 years ago

In a race, the mean time for three runners was 12.4 seconds and the mean

Ne4ueva [31]

Answer:

11.8

Step-by-step explanation:

3(12.4) + 6(11.5) = 37.2 + 69 = 106.2

106.2/9 = 11.8

4 0

3 years ago

In a certain game, a player can solve easy or hard puzzles. A player earns 30 points for solving an easy puzzle and 60 points fo

Aleksandr-060686 [28]

Answer: Second option.

Step-by-step explanation:

Let be "e" the number of easy puzzles Tina solved and "h" the number of hard puzzles Tina solved.

Set up a system of equations:

$\left \{ {{e+h=50} \atop {30e+60h=1,950 }} \right.$

You can use the Eliminationn Method to solve this system of equations:

Multiply the first equation by -30.
Add the equations.
Solve for "h".

Therefore, through this proccedure, you get:

$\left \{ {-30e-30h=-1,500} \atop {30e+60h=1,950 }} \right.\\.........................\\30h=450\\\\h=\frac{450}{30} \\\\h=15$

6 0

3 years ago