Question

(c)
Rs.5,97
Divide 12.50 into five parts in A.P. such that the first part and the last part are in the ratio of 2:3.
(a) 2, 2.25, 2.5, 2.75, 3
(b) -2,-2.25 -2.5, -2.75, -3
(c)
4, 4.5, 5, 5.5, 6
(d) -4.-4.5.-5.-5.5, -6
of the nth term is:​

Answer 1

Answer:

a)2, 2.25, 2.5, 2.75, 3

Step-by-step explanation:

Let the first term be 2x and last term be 3x

so, a(1st) = 2x and a(5th) = 3x

We know that,

a(nth) = a + (n - 1)d

so,

a(5th) = a + (5 - 1)d

3x = 2x + 4d

3x - 2x = 4d

x = 4d-----1

also, we know that sum of these terms must be 12.50

so, S(5th) = 12.50

we know that, S(nth) = (n/2)[a + l]

where l = last term and a = first term

so,

12.50 = (5/2) × [2x + 3x]

12.50 × 2 = 5[5x]

25/5 = 5x

5 = 5x

x = 1-----2

From eq. 1 and eq.2 we get

4d = 1

d = (1/4) = 0.25

so, the A.P. will be 2, 2.25, 2.5, 2.75, 3

Hope you understood it........All the best