Current location - Training Enrollment Network - Mathematics courses - The school bought 25 prizes for the students who won the math contest, with a total cost of 140 yuan. How many first prize and second prize did you buy?
The school bought 25 prizes for the students who won the math contest, with a total cost of 140 yuan. How many first prize and second prize did you buy?
First prize 8 yuan, second prize 4 yuan. If they are all second prizes, then (4 )*( 25 )=( 100), that is, 140-( 100 )=( 40) The first prize is four yuan more than the second prize, so (40) is divided by (4). So we used the (15) second prize.
Here is the equation. . .
Suppose: there are x first prizes, which can be obtained from the questions.
8x+ 4(25-x)= 140
8x+ 100-4x= 140
4x=40
x= 10
Second prize: 25- 10= 15 copies.
A: The first prize bought 10, and the second prize bought 15.