1. Mr. Li did some push-ups on Monday and Tuesday. On Tuesday, he did 300 push-ups, which was three

times the difference of the number of push-ups he did on Monday and the number 50. How many push-

ups did he do on Monday?

Mr. Li did 150 push - ups on Monday.

Solution:

Given, Mr. Li did some push-ups on Monday and Tuesday.

On Tuesday, he did 300 push-ups,

Which was three times the difference of the number of push-ups he did on Monday and the number 50.

We have to find how many push - ups did he do on Monday?

Let the number of push - ups on Monday be n

Now, three times the difference of n and 50 = 300

3 x (n - 50) = 300

n - 50 = 100

n = 150

Hence, he did 150 push - ups on Monday.