A company accountant estimates that train fares for business trips next year will increase by 10 percent, and airfares for business trips will increase by 15 percent. This year total train fares for business trips were $7,500, and total airfares for business trips were $11,200. According to the accountant's estimates, if the same business trips will be made next year as this year, how much money should be allotted for train fares and airfares next year?

A. $18,700
B. $20,570
C. $20,945
D. $21,130
E. $21,505

The OA is option D.

I don't have this PS question clear. May any expert help me here? I'd be thankful.

Hi Vincen,
Let's take a look at your question.

$$\text{Total train fares for business trips}\ =\ 7,500$$
$$\text{Total air fares for business trips}\ =\ 11,200$$

$$\text{10% increase in train fares}\ =\ 7,500\times\frac{10}{100}=750$$
$$\text{Total train fares for business trips after 10% increase}\ =\ 7,500 + 750=8,250$$

$$\text{15% increase in air fares}\ =\ 11,200\times\frac{15}{100}=1,680$$
$$\text{Total air fares for business trips after 15% increase}\ =\ 11,200+1,680=12,880$$

$$\text{Total money that need to be allotted for train and air fares next year}\ =\ 8,250+12,880=21,130$$

Therefore, Option D is correct.

Hope it helps.
I am available if you'd like any follow up.