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Let "a" be the number of the type A items, and let "b" be the number of the type B items.
Then from the condition, you have these two equations
3a + 4b = 1620 minutes (1) (1620 = 27 hours * 60 minutes, the time spent)
2a + 4b = 1400 dollars (2) (Cost of the material).
To solve the system of equations, from equation (2) subtract equation (1). You will get
3a - 2a = 1620 - 1400, or
a = 220.
Next, substitute the found valu of a= 220 into equation (2). You will get
2*220 + 4b = 1400,
4b = 1400 - 2*220 = 960
b = 960/4 = 240.
ANSWER. 220 items of the type A and 240 items of the type B.
Solved.