Question
If the product of two numbers is 60 and the sum of
their squares is 169, then what is the sum of these two numbers?Solution
Let the two numbers be x and y Then, ATQ: xy = 60    ----eq.(1) x2+ y2 = 169    ----eq.(2) Also, (x + y)2 = x2 + y2 + 2xy ⇒ (x + y)2 = 169 + (2 × 60); From eq.1 and eq.2 ⇒ (x + y)2 = 289 ⇒ x + y = 17 ∴ Sum of the two numbers = 17
24, 42, 60, ?, 96, 114
What will come in place of (?) question mark in the given number series.
10, 17, 26, 37, 50, ?
660, 653, 639, 618, 590, ?
What will come in place of the question mark (?) in the following series?
75, 219, 388, ?, 809, 1065168, 178, ?, 273, 400, 618, 963
60   61    57   66    ?      75    39
...What will come in place of the question mark (?) in the following series?
2, 5, 14, 41, 122, 365, ?
81, 83, 87, 95, 111, ?
What will come in place of the question mark (?) in the following series?
400, 841, 1202, ?, 1716, 1885
64, 66, 69, 74, 81, ?
