In which year, the total production of cars of types `P` and `Q` together was equal to the total production of cars of types`R` and `S` together?

Options

A. 1990
B. 1991
C. 1994
D. 1993

Answer

To solve the problem of determining in which year the total production of cars of types P and Q was equal to the total production of cars of types R and S, we can follow these steps:

### Step 1: Gather the data
We need to collect the production data for each type of car (P, Q, R, S) for the years provided: 1989, 1990, 1991, 1992, 1993, and 1994.

### Step 2: Calculate the total production for P and Q
For each year, we will add the production numbers of cars of type P and type Q together.

- **For 1989:** P = 8, Q = 16 → Total P + Q = 8 + 16 = 24
- **For 1990:** P = 20, Q = 10 → Total P + Q = 20 + 10 = 30
- **For 1991:** P = 17, Q = 6 → Total P + Q = 17 + 6 = 23
- **For 1992:** P = 16, Q = 14 → Total P + Q = 16 + 14 = 30
- **For 1993:** P = 16, Q = 10 → Total P + Q = 16 + 10 = 26
- **For 1994:** P = 17, Q = 12 → Total P + Q = 17 + 12 = 29

### Step 3: Calculate the total production for R and S
Similarly, we will add the production numbers of cars of type R and type S together for each year.

- **For 1989:** R = 21, S = 4 → Total R + S = 21 + 4 = 25
- **For 1990:** R = 30, S = 17 → Total R + S = 30 + 17 = 47
- **For 1991:** R = 6, S = 16 → Total R + S = 6 + 16 = 22
- **For 1992:** R = 14, S = 16 → Total R + S = 14 + 16 = 30
- **For 1993:** R = 21, S = 12 → Total R + S = 21 + 12 = 33
- **For 1994:** R = 13, S = 20 → Total R + S = 13 + 20 = 33

### Step 4: Compare totals for P + Q and R + S
Now we compare the totals calculated for P + Q and R + S for each year to find out when they are equal.

- **1989:** P + Q = 24, R + S = 25 (not equal)
- **1990:** P + Q = 30, R + S = 47 (not equal)
- **1991:** P + Q = 23, R + S = 22 (not equal)
- **1992:** P + Q = 30, R + S = 30 (equal)
- **1993:** P + Q = 26, R + S = 33 (not equal)
- **1994:** P + Q = 29, R + S = 33 (not equal)

### Conclusion
The total production of cars of types P and Q was equal to the total production of cars of types R and S in the year **1992**.

### Final Answer
The answer is **1992**.

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