Kayla is thinking of a 3-digit number. * It is divisible by 18. * It is a palindrome (It reads the same left-to-right as it does right-to-left, like 252 and 848). * It is one less than a multiple of 5. What is Kayla’s number?

Step-by-step explanation:

Let the number be aba as it is a palindrome

It divisible by 18, so it is an even number with sum of digits divisible to 9

It is one less than a multiple of 5:

Multiple of 5 will end with 0 or 5, it has to be 5 as a is even, then:

The number 4b4 is divisible by 9 only if b = 1:

So the number is:

Lets verify:

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x