Question
The cost of 2 pencils and 3 pens is RS. 55 and the cost
of 7 pencils and 2 pens is RS. 65. What is the total price (in RS) of 2 pens and one pencil?Solution
let the price of one pencil = x and the price of one pen = y ATQ- 2x + 3y = 55 .... (1) 7x +2y = 65 ......(2)  Eq (1) multiplied by 2 and eq (2) multiplied by 3. 4x +6y = 110 21x +6y =195 17x = 85 x = 5 put the value of x in eq (1) y =15 now price of 2 pencils + 1 pens =2 × 15+5= 35
5, 12, 24, 36, 52, ?
161Â Â Â Â 173Â Â Â Â Â Â 191 Â Â Â Â Â Â 215Â Â Â Â Â Â 245 Â Â Â Â Â Â ?
...81 72 136 111 ? 278
...8Â Â Â 8Â Â Â 12Â Â Â 24Â Â Â Â 60Â Â Â Â Â ?
12, 36, 80, 164, 328, ?
10, 94, 115, 138, 163, ?
Find the missing number in the given number series.
130, 152.5, 177, 203.5, 232, ?Â
65, 90, 140, ?, 315, 440
562, 628, 698, ?, 850
64Â Â Â Â 32Â Â Â Â Â Â 32 Â Â Â Â Â Â 48Â Â Â Â Â Â 96 Â Â Â Â Â Â ?
...