The sum of first 24 terms of the AP a1,a2,a3, if it is known that a1+ - Maths - Arithmetic Progressions

Question

The sum of first 24 terms of the AP a 1
,a 2 ,a 3
,…… if it is known that a 1
+ a 5 +a 10
+a 15 +a 20
+a 24 =225, is equal
to????????

Amarsen · Accepted Answer

a1 + a5 + a10 + a15
+ a20 + a24 = 225
a + a + 4d + a + 9d + a + 14d + a + 19d + a + 23d = 225
6a + 69d = 225
2a + 23d = 75( deviding by 3) (i)
S24 = 12( 2a + 23d)
= 12 X 75 = 900

The sum of first 24 terms of the AP a 1 ,a 2 ,a 3 ,…….. if it is known that a 1 + a 5 +a 10 +a 15 +a 20 +a 24 =225, is equal to????????

The sum of first 24 terms of the AP a ₁ ,a ₂ ,a ₃ ,…….. if it is known that a ₁ + a ₅ +a ₁₀ +a ₁₅ +a ₂₀ +a ₂₄ =225, is equal to????????