Correct Answer: 27 (3/7) hrs Explanation: Let capacity of tank = 12 lit A+B+C per hr = 12/12 = 1 In 3 hrs = 1*3 = 3 Remaining = 12-3 = 9 lit Filled by A+B in 16 hrs Efficiency of A +B = 9/16 Efficiency of C = 1 - 9/16 = 7/16 C will fill full tank in = 12/(7/16) = 192/7 = 27(3/7) hrs

## Q. Three pipes A, B and C can fill a …

## Navya

Correct Answer: 27 (3/7) hrs Explanation: Let capacity of tank = 12 lit A+B+C per hr = 12/12 = 1 In 3 hrs = 1*3 = 3 Remaining = 12-3 = 9 lit Filled by A+B in 16 hrs Efficiency of A +B = 9/16 Efficiency of C = 1 - 9/16 = 7/16 C will fill full tank in = 12/(7/16) = 192/7 = 27(3/7) hrs

## Q. Find the number of zeros in the following multiplication: …

## Navya

Correct Answer: 11 Explanation: (25*75*125)*128*(50*100*150) =(5*5*3*5*5*5*5*5)*(2*2*2*2*2*2*2)*(50*100*150) = Pair of (2*5) = 7 zeros and remaining 4 zeros Total = 11 zeros

## Q. In the adjoining figure, AB, EF and CD are …

## Ritika

Correct Answer: 9 cm Explanation: 10/5 = 18/EF EF = 9 cm.

## Q. The total surface area of a solid right circular …

## Ritika

Correct Answer: 4:9 Explanation: Surface areas = 2πr(r+h) = 2*4πr² r+h = 4r h = 3r Volume - 4/3 * π*r³ : πr²*h 4/3 : 3 4 : 9

## Q. From the right circular cylinder of radius 10 cm …

## Ritika

Correct answer: 21 cm Explanation: 1/3 * π *10²*H = π*10²*21 - 40/400 22H/21 = 66 - 44 H = 21*22/22 H = 21 cm.

## Q. The sum of interior angles of a regular polygon …

## Ritika

Correct Answer: 35 Explanation: (n-2)*180 = 1440 N = 10 Diagonals = n(n-3)/2 = 10*7/2 = 35

## Q. Anil borrowed some money at the rate of simple …

## Ritika

Correct Answer: None of these Explanation: SI = (15*4 + 12*5 + 13*7) = 211% of P =78850 rupees So P = 37,369

## Q. Base of a right pyramid is a square. Length …

## Ritika

Correct Answer: 9m Explanation: Side of base = 24√2/√2 = 24 m Area of base = 24*24 = 576 m² Volume of pyramid = 1728 576*height/3 = 1728 Height = 9 m.

## Q. In an exam, the average marks obtained by the …

## Ritika

Correct Answer: 400 Explanation: Let total students = X According to question- (120X - 250*80)/X = 70 50x = 20000 X = 400 students

## Q. A right pyramid of 10 m height has a …

## Ritika

Correct answer: 150 m² Explanation: Side of base = 10/√2 = 5√2 m Slang height of pyramid = √(10²+ (5/√2)²) = √(225/2) = 15/√2 Area of 1 side surface = 1/2 *(15/√2)*5√2 = 75/2 m² Of all = 4*75/2 = 150 m²