Aschool 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. how many ways can the students be seated if all of the second-grade students occupy the first row?

25p20
5p5 × 20p15
5c5 × 25c14
5p5 × 15p15
5p5 × 25c15

First row: permutation of 5 seats taken 5 (second grade students) at a time (second grade students) => 5P5

Other 4 rows: permutation of 20 seats taken 15 (first grade students) at a time => 20P15

Total different ways: 5P5 * 20P15

Sorry i don't really know and i don't have time

Hello!

the answer is:

the correct option:

b.

why?

to solve the problem, we need to remember how to operate to simplify exponential expressions using the logarithms.

we are given the equation:

then, using placing logarith with base 7 on both sides of the equation, we have:

so, rounding the obtained result to two decimal places (nearest hundreth), we have:

hence, we have that the correct option:

b.

have a nice day!