Advertisements
Advertisements
प्रश्न
The ratio of boys and girls in a school is 12 : 5. If the number of girls is 840, the total strength of the school is
विकल्प
1190
2380
2856
2142
उत्तर
2856
Ratio of boys and girls = 12:5
Let x be any number such that the number of boys and girls are 12x and 5x, respectively.
Number of girls = 840
5x = 840
⇒ x = `840/5` = 168
Number of boys = 12x= 12 × 168 = 2016
Number of girls = 840
Total strength of the school = 2016 + 840 = 2856
APPEARS IN
संबंधित प्रश्न
Find the third proportional to `x/y + y/x` and `sqrt(x^2 + y^2)`
If `x = (sqrt(a + 3b) + sqrt(a - 3b))/(sqrt(a + 3b) - sqrt(a - 3b))`, prove that: 3bx2 – 2ax + 3b = 0.
Find two numbers such that the mean proportional between them is 14 and third proportional to them is 112.
If u, v, w, and x are in continued proportion, then prove that (2u+3x) : (3u+4x) : : (2u3+3v3) : (3u3+4v3)
`("pqr")^2 (1/"p"^4 + 1/"q"^4 + 1/"r"^4) = ("p"^4 + "q"^4 + "r"^4)/"q"^2`
If a : b = c : d, show that (a - c) b2 : (b - d) cd = (a2 - b2 - ab) : (c2 - d2 - cd).
Find the fourth proportional to 9.6 kg, 7.2 kg, 28.8 kg
If b is the mean proportional between a and c, prove that a, c, a² + b², and b² + c² are proportional.
If a + c = mb and `(1)/b + (1)/d = m/c`, prove that a, b, c and d are in proportion.
If a, b, c and d are in proportion, prove that: `(a^2 + ab)/(c^2 + cd) = (b^2 - 2ab)/(d^2 - 2cd)`
If a, b, c and d are in proportion, prove that: `(a^2 + ab + b^2)/(a^2 - ab + b^2) = (c^2 + cd + d^2)/(c^2 - cd + d^2)`
