Question

Una ONG tiene la finalidad de mejorar las condiciones de salud de personas en estado de pobreza.Si todos los meses se incorporan 5 personas y al final del primer mes hay 125 voluntarios, ¿cuántas personas trabajaran como voluntarios en la ONG al cabo de 2 años y medio?

Answer 1

After two and a half years, there would be 210 volunteers.

Explanation:

Givens

• Each month there are added 5 people.
• The first month there are 125 volunteers.

These problem models a arithmetic sequence, where the difference is 5 and the first term is 125.

Notice that 2 and a half year are equivalent to 18 months. That means we need to find the 18th term,

A arithmetic sequence is defined as

`a_(n)=a_(1)+(n-1)d`

Where
`d=5`,
`a_(1)=125` and
`n=18`.

`a_(18)=125+(18-1)5=125+(17)5=125+85=210`

Therefore, after two and a half years, there would be 210 volunteers.