Answer:
5P5×20P15
Step-by-step explanation:
A school bus has 25 seats, with 5 rows of 5 seats.
15 students from the first grade and 5 students from the second grade travel in the bus.
second-grade students occupy the first row.
The 5 students of second grade are to be seated in 5 seats,this can be done in:
5P5 ways where P is the permutation
Now 15 students from first grade are to be arranged in remaining 20 seats
This can be done in:
20P15 ways
Hence, total ways student can be seated is:
5P5×20P15
ANSWER
Find out the how much fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
To proof
let us assume that the fluid should be drained and replaced with pure antifreeze be x .
As given
A radiator contains 10 quarts of fluid, 30% of which is antifreeze.
Now write 30% in the decimal form

Now write 60% in the decimal form

After drained and replaced the fluid with pure antifreeze than the quantity becomes = ( 10 - x )
The quantity of antifreeze is

The fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
than the equation becomes

solyving
100x +300 - 30x = 600
70x = 300

x = 4.28 quarts (approx)
Hence 4.28 quarts (approx) fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
Therefore the option (c.) is correct .
1) 6x-7y=-11
2) x=-2
3) y=-4x+1
4) y-5=3(x-1)
A
E
And
F
They all add up to under 32.