ICSE-VIII-Mathematics

05: Playing with Number Class 8 Maths

with Solutions - page 4
Qstn# D-11 Prvs-Qstn
  • #11
    5 × 2 is a multiple of 11?
    Ans : Sum of digit in even place = x
    And sum of the digits in odd place = 5 + 2 = 7
    Difference of the sum of the digits in even places
    And in odd places = x - 7
    5 × 2 is a multiple of 11
    ⇒ x - 7 = 0, 11, 22
    ⇒ x - 7, 18, 29,
    Since, x is a digit x = 7