Find the largest number that will divide 398, 436 and 542 leaving remainders 7, 11, and 15 respectively.

• 17

• 15

• 19

• 22

Answer explanation

Subtract the remainders and then find the HCF of the resulting numbers

The decimal expansion of the rational number  $\frac{43}{2^45^3}$  will terminate after how many places of decimals?

• 3

• 4

• 5

• will not terminate

If the HCF of 408 and 1032 is expressible in the form 1032 × 2 + 408 × p, then find the value of p.

• 5

• 20

• -20

• -5

Find LCM of numbers whose prime factorisation are expressible as 3 × 52 and 32 × 72. (2014)

• 10025

• 120025

• 11025

• 10115

Find the HCF (865, 255) using Euclid’s division lemma. (2013)

• 5

• 860

• 255

• 15

Find the largest number which divides 70 and 125 leaving remainder 5 and 8 respectively. (2015)

• 25

• 13

• 125

• 70

Complete the following factor tree and find the composite number x and y respectively. (2014)

• x = 65 , y = 65

• x = 585 , y = 585

• x = 65 , y = 585

• x = 585 , y = 65

Three bells toll at intervals of 9, 12, 15 minutes respectively. If they start tolling together, after what time will they next toll together? (2013)

• 3 hours

• 2.5 hours

• 4.15 hours

• 2 hours

Answer explanation

Find LCM in such situations

Two tankers contain 850 liters and 680 liters of petrol. Find the maximum capacity of a container which can measure the petrol of each tanker in the exact number of times. (2012)

• 10

• 170

• 850

• $850\times680$
  

Answer explanation

Find HCF to find maximum capacity

The length, breadth, and height of a room are 8 m 50 cm, 6 m 25 cm and 4 m 75 cm respectively. Find the length of the longest rod that can measure the dimensions of the room exactly. (2015)

• 25 m

• 65 cm

• 25 cm

• 6.5 m

Answer explanation

Find HCF to find maximum/largest/biggest