Cubic functions usually look like an S
Another way is to note that there are <span><span>(<span>104</span>)</span><span>(<span>104</span>)</span></span> (“10 choose 4”) ways to select 4 balls from a collection of 10. If 4 of those 10 balls are “special” in some way (in this case, “special” = “red”), then the number of ways to choose 4 special balls is <span><span>(<span>44</span>)</span><span>(<span>44</span>)</span></span>. (The factor of <span><span>(<span>60</span>)</span><span>(<span>60</span>)</span></span> is included to convey that, after choosing 4 special balls, we choose none of the 6 non-special balls.) This line of reasoning gives the second expression.
Answer:
12
Step-by-step explanation:
12 dimes is $1.20, so your total for the quarters is $3.25. Since there are 25 coins total and 12 of them are dimes, 25 - 12 = 13, so you have 13 quarters. 13 times its value of 25 cents leaves you with $3.25, fulfilling your needed total.
There likely was an easier way to do this, but I'm unfamiliar with it so I ended up doing this.