How Many Terms Are There In An A.p. Whose First And Fifth Terms Are -

1.	How Many Terms Are There In An A.p. Whose First And Fifth Terms Are -14 And 2, Respectively, And The Sum Of Terms Is 40 ?
Answer» Now the common difference of this AP is 16/4 = 4. The sum of an AP is N/2 {2A + (n – 1)d} Substituting we get, 40 = n/2 {2×-14 + (n – 1)4} The best way to SOLVE this is by plugging options. Put in n = 10 and get the RHS as 40. Now the common difference of this AP is 16/4 = 4. The sum of an AP is n/2 {2a + (n – 1)d} Substituting we get, 40 = n/2 {2×-14 + (n – 1)4} The best way to solve this is by plugging options. Put in n = 10 and get the RHS as 40.

How Many Terms Are There In An A.p. Whose First And Fifth Terms Are -14 And 2, Respectively, And The Sum Of Terms Is 40 ?

Answer»

Now the common difference of this AP is 16/4 = 4.

The sum of an AP is N/2 {2A + (n – 1)d}

Substituting we get, 40 = n/2 {2×-14 + (n – 1)4}

The best way to SOLVE this is by plugging options. Put in n = 10 and get the RHS as 40.

Now the common difference of this AP is 16/4 = 4.

The sum of an AP is n/2 {2a + (n – 1)d}

Substituting we get, 40 = n/2 {2×-14 + (n – 1)4}

The best way to solve this is by plugging options. Put in n = 10 and get the RHS as 40.