Question
The sum of three numbers in AP is 21, and their product
is 315. Find the numbers.Solution
ATQ,
→ Let (a − d), a, (a + d). Sum = 3a = 21 ⇒ a = 7. Product = (7 − d)·7·(7 + d) = 315 ⇒ 7(49 − d²) = 315 ⇒ 49 − d² = 45 ⇒ d² = 4 ⇒ d = 2. Numbers: 5, 7, 9
Find the missing number in the given number series.
98, 89, 114, 50, 194, ?
0, 6, 24, ?, 120, 210
40   41    37   46    ?      55    19
...What will come in place of the question mark (?) in the following series?
4, 8, 24, ?, 480, 2880
140, 146, 158, 176, ?, 230
8, 15, 44, 175, 874, ?
In each of the following number series, one term is missing. Find the missing term.
7, 14, 28, 56, 112, ?
What will come in place of the question mark (?) in the following series?
92, 153, 220, ?, 364, 443
1500 Â Â Â 150Â Â Â 30Â Â Â ? Â Â Â Â 3.6Â Â Â Â 1.8
64, 32, 48, 120, 420, ?
