Advertisements
Advertisements
प्रश्न
The sum of three numbers in A.P. is 30 and the ratio of first number to the third number is 3 : 7. Find the numbers.
उत्तर
Sum of three numbers in A.P. = 30
Ratio between first and the third number = 3 : 7
Let numbers be
a – d, a, a + d, then
a – d + a + a + d = 30
⇒ 3a = 30
⇒ a = `(30)/(3)` = 10
and
`"a - d"/"a + d" = (3)/(7)`
⇒ 7a – 7a = 3a + 3d
⇒ 7a – 3a = 3d + 7d
⇒ 4a = 10d
⇒ 10d = 4 x 10 = 40
⇒ d = `(40)/(10)` = 4
∴ Numbers are 10 – 4, 10, 10 + 4
⇒ 6, 10, 14.
APPEARS IN
संबंधित प्रश्न
Split 207 into three parts such that these parts are in A.P. and the product of the two smaller parts in 4623.
The sum of three numbers in A.P. is 15 and the sum of the squares of the extreme terms is 58. Find the numbers.
`1/a, 1/b` and `1/c` are in A.P. Show that : bc, ca and ab are also in A.P.
Insert four A.M.s between 14 and -1.
Q.2
Q.5
Q.7
Divide 216 into three parts which are in A.P. and the product of two smaller parts is 5040.
How many two digit numbers are divisible by 3?
Find the indicated terms in each of following A.P.s: – 4, – 7, – 10, – 13, …, a25, an
