Question

if the common difference of an AP whose first term is 4 the last term is 49 the sum of all its term is 265

Answer 1

The answer is 5 acc. to formula Sum=number of terms /2*(2*first term+(no. of terms-1)*common difference)

Answer 2

Hi Friends ✋✋

We are given

First term , a = 4

Last term, l = 49

Sum = 265

S = n/2 [ a + l ]

265 = n/2 [ 4 + 49 ]

530 = 53n

n = 10

l = a + ( n - 1 ) × d

49 = 4 + ( 10 - 1 ) × d

45 = 9 × d

d = 5


Hope it helps