Question
If the 5-digit number 693XY is divisible by 3, 7, and
11, then what is the value of X + 2Y?Solution
ATQ;
The 5-digit number 693XY is divisible by 3, 7, and 11.
Divisibility rule of 3: The sum of digits must be a multiple of 3.
6+9+3+X+Y=18+X+Y
So, X + Y must be one of {0, 3, 6, 9, 12, 15, 18}.
Divisibility rule of 11: The difference between the sum of alternate digits must be divisible by 11.
(6+3+Y)−(9+X)=0
9+Y−9−X=0
Y−X=0
X=Y
From X + Y = 6, and X = Y, we get:
2X=6⇒X=3,Y=3
Checking divisibility by 7:
The number 69333 is divisible by 7.
Finding X + 2Y:3+2(3)=3+6=9
National Bureau of fish genetic resource situated at ___
Match List I with List II
Choose the correct answe...
What does the term "bioenergetics" refer to in the context of ecosystems?
Which colour of the tag is used for foundation stage seed?
As per BIS standard, pasteurized milk should have standard plate count not exceeding
What term describes the interaction where one organism kills and eats another organism?
Field capacity is the upper limit of available soil moisture. At field capacity, how much is the suction pressure?
Insects are studied in .......................................?
Absorptive organ in plant embryoÂ
Which of the following is/are correct regarding correlation?