Integers

[danjuma]

6. A child selected a 3 digit number XYZ, where X , Y and Z denote the digits of the number. If no 2 of the 3 digits were equal , what was the 3 digit number?

a. The sum of the digits was 10.

b. X<Y<Z

[beatthegmatinsept]

IMO E

You get different combinations of numbers with a and b together,
For example,
136
145

[Gurpinder]

6. A child selected a 3 digit number XYZ, where X , Y and Z denote the digits of the number. If no 2 of the 3 digits were equal , what was the 3 digit number?

a. The sum of the digits was 10.

b. X<Y<Z

(a)
we can have 721 or, 631 or the other way around hence insufficient.

(b)
we can have 127 or 136 - hence insufficient

together
the possibilities that make 10 are

127
136
019

hence (E)