Question

which term of the A.P 1,4,7........is 88​

Answer 1

Step-by-step explanation:

Given -

• AP is 1, 4, 7,......

To Find -

• Which term of the AP is 88

As we know that :-

• an = a + (n - 1)d

⇝88 = 1 + (n - 1)3

⇝87 = 3n - 3

⇝3n = 90

⇝n = 30

Hence,

30th term of AP is 88.

Verification :-

• an = a + (n-1)d

⇝a_{30} = 1 + (30 - 1)3

⇝a_{30} = 1 + 29×3

⇝a_{30} = 1 + 87

⇝a_{30} = 88

Hence,

Verified...

Answer 2

$\bf \huge \underline \red { \: Answer:- \: }$

$\bf \: 1,4,7.... \: is \: an \: ap$

Here,

a=1

$\bf \: a_2 = 4$

$\bf \: a_3 = 7$

$\bf \: d = a_2 - a_1 \\ \bf \: d = 4 - 1 = 3$

$\bf \: first \: term \: a = 1 \\ \bf \: common \: difference \: d = 3$

$\bf \huge \fbox \green { \: A_n = a + ( n - 1)d \: }$

$\bf \: 88 = 1 + (n - 1)3$

$\bf \: 88 = 1 + 3n - 3$

$\bf \: 88 = 3n - 2$

$\bf \: 3n = 88 + 2$

$\bf \: 3n = 90$

$\bf \: n = \frac{90}{3}$

$\bf \: n = 30$

$\bf \pink{ \therefore \: 30 \: th \: term \: is \: 88}$