At 140 sit-ups, both conditions are met.
We can solve this problem by treating the equations we are given as two dependent equations, meaning that now we have a system of equations. The easiest way to solve this system is to use substitution. We can do this because we already know what s is equal, expressed in p. Since s = 4p, we can substitute that in our other equation.
5p = 175
Get p by itself
5/5p = 175/5
p=35
Now we can substitute the value of p in either of the equations. Since we know that s = 4p, s = 35 * 4 = 140. That means the answer to our problem is 140 sit-ups.
