8/15
11/25
12/25
13/25
Correct answer is D
First teacher received \(\frac{2}{5}\) ∴Remainder \(= 1 - \frac{2}{5} = \frac{3}{5}\)
2nd teacher received; \(\frac{2}{15} of \frac{3}{5} = \frac{2}{15} \times \frac{3}{5} = \frac{2}{25}\)
3rd teacher will receive; \(1-\frac{2}{5}-\frac{2}{25}=\frac{25-10-2}{15}\\=\frac{13}{25}\)
96 cm
324 cm
36 cm
144 cm
Correct answer is B
\(L \propto T^2\)
\(L = kT^2\)
\(k = \frac{L}{T^2}\)
when T = 4, L = 64.
\(k = \frac{64}{4^2} = 4\)
\(L = 4T^2\)
when T = 9,
\(L = 4 \times 9^2 = 324cm\)
Find the sum to infinity of the series 1/2 , 1/6, 1/18, .....
2/3
1/3
3/4
1
Correct answer is C
\(a=\frac{1}{2}\\r=\frac{\frac{1}{6}}{\frac{1}{2}}=\frac{1}{6}\times\frac{2}{1}=\frac{1}{3}\\S_\infty = \frac{a}{1-r}\\S_\infty = \frac{\frac{1}{2}}{1-\frac{1}{3}}\\=\frac{\frac{1}{2}}{\frac{3}{2}}\\=\frac{1}{2}\times\frac{3}{2}\\=\frac{3}{4}\)
Factorize completely ac - 2bc - a
(a - 2b)(c - a - 2b)
(a - 2b)(c + a +2b)
(a - 2b)(c - a + 2b)
(a - 2b)(c + a - 2b)
Correct answer is A
ac - 2bc - a2 + 4b2
ac - 2bc - (a2 - 4b2)
ac - 2bc - (a2 -(2b)2)
c(a - 2b) - {(a - 2b)(a + 2b)}
(a - 2b)(c - (a + 2b))
(a - 2b)(c - a - 2b)
18
12
6
3
Correct answer is A
Qn = 3 * 2n - 2
Um = 3 * 22m - 3
Q2 * U2 = (3 * 22 - 2) * (3 * 22(2) - 3)
= 3 * 20 * 3 * 21
= 3 * 1 * 3 * 2
= 18