Answer:
2
Step-by-step explanation:
There are 13 girls and 4 more students that are boys that made an A grade. Thus there are 13+4=17 students that are either girls or A students.
The probability of choosing a girl or A student is 17/30.
Answer:
a = 33 degrees, b = 147 degrees
Step-by-step explanation:
The sum of all the angles in a triangle is 180 degrees, and to solve for the angle on the other side of 109 degrees is 71 degrees, so to solve for a, have 180 minus 71 and 76. Then the sum of 71 and 76 is angle b since its the result of a subtracting from 180.
Step-by-step explanation:
9.1k=64.7
Find k
64.7/9.1=7
Plug in 7
9.1(7)=64.7
Multiply 9.1 and 7=63.7
63.7=64.7
Divide
1.02 or 1 1/50
Hope that helps somewhat
Answer:
n = 60.22
Step-by-step explanation:
Hello
To find Sn, we need to draw out equations for each a₇ and a₁₉
In an arithmetic progression,
Sn = a + (n-1)d
Where Sn = sum of the A.P
a = first term
d = common difference
a₇ = 32
32 = a + (7-1)d
32 = a + 6d ........equation (i)
a₁₉ = 140
140 = a + (19-1)d
140 = a + 18d .........equation (ii)
Solve equation (i) and (ii) simultaneously
From equation (i)
32 = a + 6d
Make a the subject of formula
a = 32 - 6d .....equation (iii)
Put equation (iii) into equation (ii)
140 = (32 - 6d) + 18d
140 = 32 - 6d + 18d
Collect like terms
140 - 32 = 12d
12d = 108
d = 108 / 12
d = 9
Put d = 9 in equation (i)
32 = a + 6(9)
32 = a + 54
a = 32 - 54
a = -22
When Sn = 511
Sn = a + (n - 1)d
Substitute and solve for n
511 = -22 + (n-1) × 9
511 = -22 + 9n - 9
511 = -31 + 9n
511 + 31 = 9n
542 = 9n
n = 542 / 9
n = 60.22
