Respuesta :

Answer:

In total 5 packets of rubber bands are needed.

Out of which 5 rubber bands are left.

Step-by-step explanation:

The number of rubber bands needed by 1 student  = 5

The total number of students  = 8

So, the total rubber bands needed by all students

=  Total students   x Number of rubber bands needed by 1 student

= 8 x 5  = 40 bands

Now 1 packet of rubber bands  = 9 bands

⇒ 2 packets  = 2 x ( 9 bands) = 18  bands

⇒ 3 packets  = 3 x ( 9 bands) = 27  bands

Similarly, 4 packets  = 36 bands , 5 packets  = 45 bands

Now, if we buy 4 packet of bands, there are 36 rubber bands which are LESS THAN THE TOTAL STUDENTS.

So, we buy 5 packets.

We have in total  45 bands, but the total students = 40

So, the number of  left rubber bands = Total bands - Total students

                                                               = 45 - 40 = 5

Hence, in total 5 packets of rubber bands are needed, and out of which 5 rubber bands are left.