Answer: 1

Explanation:
1850 is (1849 + 1)...i.e. (43)2 + 1and also (1936 - 86) i.e (44)2 – 86.So, if 1 is subtracted from 1850 or if 86 is added to 1850, we get perfect squares. SO, the least number to be added or subtracted to get a perfect square is1.

Answer: 132

Explanation:
1 and 8 are the first two digits of the divisor and 3 and 6, those of the dividend.
Hence we try 200 * 187 = 37400
Subtracting 374 twice from this, we get 36652.
We confirm that (36652 - 36520)
Also 36652 – 36520 = 132 < 187
Hence, the least number that should be added is 132

Answer: 60

Explanation:
21600 = 23 * 22 * 33 * 52
Thus 21600 should be multiplied by 2*5 to make it a perfect cube.
∴ the perfect cube number 216000
Cube root of 216000 = 2*2*3*5 = 60

Answer: Rs 40000

Explanation:
Area of the field = 1000000 sq.m
∴Side of the field = √1000000 = 1000 m
∴Perimeter of the field = 4 * 1000 = 4000 m
∴Cost = 100 * 4000 = Rs 40000

Answer: 4375

Explanation:
a2 + b2 = (a + b)2 – 2ab
∴a2 + b2 = 625 – 300 = 325
a3 + b3 = (a + b)3 – 3ab(a + b)
∴a3 + b3 = 15625 – 450(25)
a3 + b3 = 15625 – 11250 = 4375

Answer: 3600

Explanation:
LCM of 16 , 18 and 45 = 720
On multiplying 720 by 5,
We get the required number as 720 * 5 = 3600

Answer: 4

Explanation:
If x is the required number
X – 13 is divisible by 18.
∴ x – 13 is also divisible by 9
Dividing the remainder viz 13 by 9, we get the remainder 4.
Hence, the remainder when x is divided by 9 is 4

Answer: 0

Explanation:
Multiplying both sides with by xyz,we get
X + y+z = 3xyz
=> X3 + y3 + z3 - 3xyz = 0
=> ∴ (x + y + z)(x2+y2+z2 – xy – yz - xz) = 0

Answer: 81

Explanation:
Let the initial amount be a
Cost of 1 apple = a/10
Cost of 1 orange = a/15
Cost of 1 watermelon = a/2
As all the 3 types of fruits are bought, the minimum shall be 1
As oranges are the max, others are one each.
Amount spent = 6a
Hence the number of oranges
= [6a-{a/10 + a/2}] / a/15
= [6a – 6a/10] / a/15 = (54a/10) / (a/15) = 81

Answer: 40

Explanation:
Runs by bhangar – (x+10) and balls (y+5)
Runs by karthik – y and balls x
X+y+10 = 50
X+y = 40  (1)
Y+5=x-15
X-y = 20 (2)
X= 30
Runs scored by bhangar = 30 +10 = 40