Question

15. If 1/4 is subtracted from a number and the difference is multiplied by 8, the result is 24. Find the number.
16. In a class of 56 students, the number of girls is 3/5 the of the boys. Find the number of boys in the class.​

Answer 1

Answer:

$15. \: \: \: according \: to \: que$

$let \: the \: number \: be \: x \:$

$( - \frac{1}{4} + x)8 = 24$

$( \frac{ 4x - 1}{4} )8 = 24$

$4x - 1= \frac{24 \times 4}{8}$

$4x - 1= 12$

$4x = 13$

$x = \frac{13}{4}$

let the no of boy be x

girls are = 3/5 × x

56 = 3/5x + x

56= 8x/5

x = 56 × 5 ÷8

x = 35

no of boys = 35

no of girls = 3/5 ×35

= 21

Answer 2

Step-by-step explanation:

15) let the number be X and the result of subtraction be Y.

so according to question,

X- 1/4=Y. equation 1

and, Y*8=24

or, Y=3. equation 2

put equation 2 in equation 1

we get , X-1/4=3

4X- 1=12

4X =13

X= 13/4

the number be 13/4.

16) let the number of boys be X then the number of girls be 3X/5.

according to question,

X+3X/5=56

5X+3X=280

8X=280

X=35.

so so the number of boys be 35 and the number of girls be 21.