there is number X in decimal represntation whose last digit
is not 0. if digits of X are reversed then we obtain new
number say Y. both X and Y are divisible by 7. then find
all such X from 10 to 1000.

Answer Posted / sanchit

consider any 3 digit number first...
100a+10b+c
reverse it-
100c+10b+a
if these two numbers are divisible by 7 even their
difference must be
so
99(a-c) is div by 7
-> a-c=7n
c can't be 0
so possible combinations-
8,1(you can also consider n=0 ->a=c)
and 9,2 ->numbers- 952,259,861,168(palindromes-707,77,868,777)

Is This Answer Correct ?    7 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

One Train Travels 200m From A To B With 70 Km/Ph And Returns To A With 80kmph, What Is The Average Of Their Speed?

1499


From 5 different green balls, four different blue balls and three different red balls, how many combinations of balls can be chosen taking at least one green and one blue ball?

887


two trains are 2 kms apart. Speed of one train is 20m/s and the other train is running at 30 m/s. Lengths of the trains are 200 and 300m. In how much time do the trains cross each other?

747


If it takes five minutes to boil one egg, how long will it take to boil four eggs?

924


The number 0.05 is what percent of 20?

826






If x and x+10 are lengths containing right angle, what is the equation if area is 24 sq.cm

669


A chain is broken into three pieces of equal lengths containing 3 links each. It is taken to a blacksmith to join into a single continuous one. How many links are to to be opened to make it ?

805


Sum of slopes of 2 perpendicular st. lines is given. Find the pair of lines from the given set of options which satisfy the above condition?

755


How many mashes are there in 1 square meter of wire gauge if each mesh is 8mm long and 5mm wide ?

824


A ship went on a voyage.After it had travelled 180 miles a plane statrted with 10 times the speed of the ship. An army 50 miles long marches at a constant rate. A courier standing at the rear moves forward and delivers the message to the first person and then turns back and reaches the rear of the army as the army completes 50 miles. Find the distance travelled by the courier.

957


A ship is away from the shore by 180 miles.A plane is travelling at 10 times speed of the ship.How long from the shore will they meet?

1015


i need icet solved papers 2000 to 20010,and also mock papers,mock online

1859


One day the Finance minister decides that the country should have only 33 paise and 56 paise.If there are two traders having enough change in the two denominations, what is the minimum amount for which they can transact?

833


The area of the maximum size of the circle described from the 10 square inch square?

922


There is square of side 6 cm .A circle is inscribed inside the square Find the ratio of area of circle to the squqre .

730