Question

If first term ofan AP is 5, last term is 45 and the sum of the terms is 400, then the number of terms
is-​

Answer 1

Answer:

the number of terms is 16

Step-by-step explanation:

given,

first term =a=5

last term =l=45

sum of terms=400

to find=no.of terms=n

we know that, sum of all terms

s=n/2(a+l)

put all values in formula

400=n/2(5+45)

400=n/2*50

400*2=50n

800=50n

n=800/50

n=16

Answer 2

Answer:

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