Question 1199027
1) A man had two employments on the same day with the following salary condition:The first employment is #300000 per annum with annual imcrement of #12000. The second employment with annual salary of #280000 and the annual increment of #15000. The man decided that he will accept the employment that will give him more earnings in the first 15years of service. Which employment should he accept?

First employment 
$300000 per annum with annual imcrement of $12000.
Time period considered = 15 years
The yearly increment is constant =12000 
Using 
Arithmetic sequence formula for earnings  at end of 15 years

{{{ Sn = (n/2)(2a+(n-1)d) }}}

a=300000 d=12000, n=15

{{{ S15 = (15/2)(2*300000+(15-1)*12000) }}}

{{{ S15 = (15/2)(600000+(14)*12000) }}}
S15 = 5,760,000


Second employment

280000 and the annual increment of #15000
a= 280000 d=15000, n=15

S15 = (15/2)*(2*280000+(15-1)*15000

S(15)= 5,775,000

Now he can decide

 The second employment offers higher earnings in the first 15 years