Question

On Monday Anders read for a quarter hour if he and crazy amount of time he read by seven minutes each day how many hours would he have red by Friday

Answer 1

By Friday he would have read for 145 hours.

Step-by-step explanation:

Given:

Number of hours Anders read on Monday =15 minutes

Every day he increases the reading time by 7 minutes

This reading time forms an arithmetic progression

Here,

The first value is "a"=15

Common difference "d"=7

Number of days from Monday to Friday =5, Thus n=5

Number of minutes he read by Friday=sum up to 5 terms of the AP=S5

Number of times he read on Friday =a5

$a_{n} =a+(n-1)d\\\\a_{5} =a+(n-1)d\\=15+(n-1)7\\=15+(51)7\\=15+4\times7\\=15+28=43\\\\\\S_{n} =n/2(a+a_{n} )\\\\=5/2(15+43)=2.5\times 58=145\ hours$

Thus By Friday he would have read for 145 hours.