Lin and jen each thought of a number. lin thought of a 2-digit number. jen’s number is 7 times as big as lin’s. but, if lin writes 0 between the digits of her number, she’ll get jen’s number. what are the numbers?

Lin's number is 15 and Jen's number is 105.
15 is a two digit number and if we multiply it with 7, we get the answer 105.
15 x 7 = 105
And if we put 0 between the Lin's number that is 15, we will get 105
Thus, 15 and 105 are two numbers.