Study the given table and answer the question that follows.

The table shows the production of five types of cars P, Q, R, S and T by a company from the year 1989 to 1994.

Type of Car	1989	1990	1991	1992	1993	1994	Total
P	8	20	16	17	21	6	88
Q	16	10	14	12	12	14	78
R	21	17	16	15	13	8	90
S	4	6	10	16	20	31	87
T	25	18	19	30	14	27	133
Total	74	71	75	90	80	86	476

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

To find the year in which 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, we can calculate the combined production for each year and compare them.

Let's calculate the sum of production for P and Q, and the sum of production for R and S, year by year using the data given in the table:

For 1989:
Production of P and Q together = 8 + 16 = 24
Production of R and S together = 21 + 4 = 25
Since 24 ≠ 25, 1989 is not the required year.

For 1990:
Production of P and Q together = 20 + 10 = 30
Production of R and S together = 17 + 6 = 23
Since 30 ≠ 23, 1990 is not the required year.

For 1991:
Production of P and Q together = 16 + 14 = 30
Production of R and S together = 16 + 10 = 26
Since 30 ≠ 26, 1991 is not the required year.

For 1992:
Production of P and Q together = 17 + 12 = 29
Production of R and S together = 15 + 16 = 31
Since 29 ≠ 31, 1992 is not the required year.

For 1993:
Production of P and Q together = 21 + 12 = 33
Production of R and S together = 13 + 20 = 33
Since 33 = 33, the condition is satisfied.

For 1994:
Production of P and Q together = 6 + 14 = 20
Production of R and S together = 8 + 31 = 39
Since 20 ≠ 39, 1994 is not the required year.

Therefore, in the year 1993, 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.