Question

At an assembly 7 out of the first 10 students who entered the gym were carrying a backpack. Based on this information, if 700 students were at the assembly, how many students could be expected to be carrying a backpack?

Answer 1

7 out of 10 were carrying a backpack...and 3 out of 10  were not
that means 7/10 of the total students had backpacks and 3/10 of the total students did not

7/10 * 700 = 4900/10 = 490 had backpacks <==
3/10 * 700 = 2100/10 = 210 did not

Answer 2

Answer: There are 490 students who are expected to be carrying a backpack.

Step-by-step explanation:

Since we have given that

Number of students who entered the gym = 10

Number of students who carry a back pack = 7

So, part of students who carry a back pack = $\dfrac{7}{10}$

If the number of students were at the assembly = 700

So, Number of students that are expected to be carrying a backpack is given by

$\dfrac{7}{10}\times 700\\\\=7\times 70\\\\=490$

Hence, there are 490 students who are expected to be carrying a backpack.