Ñoäi vaên ngheä cuûa tröôøng coù 10 nam vaø 5 nöõ. Hoûi coù bao nhieâu caùch choïn ra 5 ngöôøi ñeå tham gia bieåu dieãn vaên ngheä; bieát:
a) Nhaát thieát phaûi coù ít nhaát 1 nam vaø 1 nöõ.
b) Coù ñuùng 2 nam, 3 nöõ vaø moät baïn nam ñöôïc choïn laøm nhoùm tröôûng.
c) Coù ñuùng 3 nam, 2 nöõ vaø baïn Huøng ñöôïc choïn laøm nhoùm tröôûng.

where are the images of the functions i can only see the question you typed.

step-by-step explanation:

step-by-step explanation:

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step-by-step explanation:

step-by-step explanation:

part a. the differences are decreasing, so we know the sequence is not arithmetic. the ratios are constant (=3/4), so we know the sequence is geometric.

part b. from part a, we know the common ratio is 3/4, so each term is 3/4 of the one before. the initial term is the number of gallons at h=1.

g[h] = (3/4)·g[h-1]

g[1] = 384 . . . . initial value required for a recursive definition

part c. the general formula for a geometric sequence is

a[n] = a[1]·r^(n-1)

we have a[1] = 384, r = 3/4, and the term number given by h. the formula that follows is

g[h] = 384·(3/4)^(h-1)

part d. filling in the value and doing the arithmetic, we have

g[12] = 384·(3/4)^11 ≈ 384·0.042235136 ≈ 16.2183 . . gallons

part e. each gallon is 4 quarts, so

16.2183 gal × 4 qt/gal = 64.8732 qt