Question

The number ABC are the digits of a 3 digit number which satisfy 49A+7B+c=286. What is the number?

Answer 1

49×5 + 7×5 + 6=286.

A= 5 , B= 5 C=6.

and the three digit number is 556

Answer 2

Answer:

556

Step-by-step explanation:

49a+7b+c=286---1

adding mod 7 at both the sides

we get

0*a + 0*b + c=280[mod7]+6                           [ we calculate mod 7 of 6 only]

therefore c=6

if we subsitute it in eqn. 1

49a+7b+c=286

49a+7b=280

if we take 7 common

7a+b=40

so only one condition can satisfy this which is 5

7*5+5=40

so 100*5+10*5+6=556 is required answer