Question

Rummoner lok a few coins from Rohit. Now, the new ratio of coins is 15: 8. How many coins does
Rohit have?
6. The ratio of the number of boys to the number of girls in a school with 840 students was 7:5. In the new
session, the number of boys increased by 20 and the ratio of boys to girls changed to 6:5. Calculate the
number of new girls.
the​

Answer 1

Answer:

Step-by-step explanation:

Let the no. of boys=7x

No. of girls=5x

7x+5x=1440

12x=1440⇒x=120

∴ No. of boys=120×7=840

No. of girls=5×120=600

Let y be the no. of girls to be added

⇒  

3

4

​  

=  

600+y

840+40

​  

⇒2400+4y=3320+120

⇒4y=3440−2400=1040

⇒y=  

4

1040

​  

=260

∴ no. of girls that needs to be added =260