Question

There are Europian and Indian soldiers, in an army of 12000 soldiers. The average height of European soldiers is 5 ft 10 inch and the average height of Indian soldiers is 5 ft 9 inch and the average height of whole army is 5ft 9 3/4 inch. What will be number of Indian soldiers in the army

Answer 1

Answer:

Step-by-step explanation:

let x and y are indian and european soldiers

then x+y=12000----(1)

total of height of indian soldiers=(5*12+9)x=69x

total of height of Europen soldiers=(5*12+10)y=70y

total of height of all soldiers=69x+70y=12000*(5*12+9 3/4)

=12000*(60+39/4)=12000*(240+39)/4=3000*279=837000

69x+70y=837000----(2)

multiply (1)by 70 we ge

70x+70y=840000---(3)

subtracting (2) from(3)

x=840000-837000=3000

y=12000-3000=9000

indian soldirers are=3000