Question

The sum of four numbers in A.P is 20. The ratio of the product of the first and the last numbers and the product of 2nd & 3rd numbers is 2:3 ; Find the numbers
.
.
.
ANSWER = 2,4,6,8 OR 8,6,4,2

Answer 1

Cant understand how to start

Answer 2

Let four numbers in AP be
a-3d ,a-d ,a+d and a+3d

Answer 3

Now,
a-3d+a-d+a+d+a+3d=20
4a=20
a=5

Answer 4

Also,
(a-3d)(a+3d)/ {(a-d) (a+d)} =2/3

Answer 5

i cant understand this sentence "The ratio of the product of the first and the last numbers and the product of 2nd & 3rd numbers is 2:3"

Answer 6

It simply means (a-3d)(a+3d)/ {(a-d) (a+d)} =2/3

Answer 7

oh

Answer 8

what should i do next.. cross multiply?

Answer 9

Now,
3(a-3d)(a+3d) =2(a-d)(a+d)
3a^2 -27d^2 =2a^2 -2d^2
a^2 =25d^2
Also a=5
5^2 =25d^2
d^2=1
d=+-1

Answer 10

Now, can u?

Answer 11

ok

Answer 12

i have to substitute the values of a and d in the four numbers which were a-3d, and so on

Answer 13

yep

Answer 14

ok got the numbers :)

Answer 15

thanks

Answer 16

welcome