Not necessarily. You could have done your multiplication wrong. Or in some cases, yes, you could have to use another skill. For example, you can't solve an optimization problem with addition, you need some calculus skills under your belt.
Answer:
Monthly interest rate is r=0,004375
Monthly principal c=590,625
Step-by-step explanation:
Monthly interest payment rate :

Now, we need to find monthly principal payment : 
Use this rule : 
P=108000
r=0,004375

There tried too draw it out of you
Answer:
4 t-shirts
Step-by-step explanation:
75-35 = 40
at most she can buy 4, because if she buys 5, she uses 45 dollars
The answer is 0.664 because you have to divide 4/5 and 5/6