Question

If a lab technician has a salary of 22000 her first year and is due to get a 500 raise each year, then what will her salary be in her seventh year?
What is the total salary for 7 years of work for the lab technician?

Answer 1

just use for formulas for an AS

term(n) = a + (n-1)d
for yours
a=22000
d=500
n=7

sum(n) = (n/2)(first + last)
(you have the last term from above)

or

sum(n) = (n/2)(2a + (n-1)d )

Answer 2

I) A.P will be
22000,22500,23000.........
a)=22000
d)=22500-22000=500
n=?
an=?

an=a+(n-1)d
=22000+(7-1)500
= 22000 + (6)500
=22000+3000
=25000
So salary at the end of 7th year will be rupees 25000


ii) total salary for 7 years

S7=n/2(2a+(n-1)d)
= 7/2(2(22000)+(7-1)500)
= 7/2 (44000+(6)500)
= 7/2 (44000+3000)
= 7/2(47000)
=7×47000/2
=329000/2
=164500

So total salary for seven years will be 164500

Answer 3

My ans is correct

Answer 4

My answer will be correct in exam