Find the greatest possible value of (a + b) for which the 8 digit number 148b205a is divisible by 15.
Answer & explanation
Correct answer: option 2
The number is 148b205a.
15 = 3 x 5
According to Divisibility rule of 5 , unit digit of the number should be 0 or 5.
Therefore, a = 0 or 5
ATQ, we have to find the greatest value, hence a = 5
According to Divisibility rule of 3 , sum of all digit of the number should be multiple of 3.
Therefore, Sum of digits = 1 + 4 + 8 + b + 2 + 0 + 5 + 5
= 25 + b
Here,
b should be = 2, 5 or 8
Here, b = 8 (to find the greatest value)
⇒ a + b = 8 + 5 = 13