Question

please answer my question ​

Answer 1

Step-by-step explanation:

=25-5-10+15+10

=25-15+25

=10+25

=25

Answer 2

Answer:

the total of the marks obtained in a quiz=75

Step-by-step explanation:

first let's find the ap

so the ap is

(25,-5,-10,15,10)

here,the first term, i.e.

( t1=25=a , t5=10=tn[since 10 is the last ,term] ,

n=5 , d= t5-t4= -10-15= -5)

thus,we have to find the total marks,so in ap total means Sn right

here 'n' indicates no. of observations

thus,n=5

so,Sn= n/2[2a+(n-1)×d]

(now let us substitute the value as given above)

S5=5/2[2×25+(5-1)×(-5)]

S5=5/2[50+4×(-5)]

S5=5/2[50-20]

S5=5/2[30]

S5=5×15

S5=75