Question

3+7+.......upto 60 terms​

Answer 1

Answer:

an = a + (n - 1) d

60 = 3 + ( n - 1) 4

15= 3 + (n -1)

12 = n-1

13 = n

Answer 2

Answer:

Ans is 7260

Step-by-step explanation:

since its an ap , we will use the formula

S=n/2[2a+(n-1)d]

Answer is in the attachment