Teacher Wang won 240 yuan, with 2 yuan 5 yuan 10 yuan, three types of RMB 50, of which 2 yuan and 5 yuan were as many as, how many RMBs of 10 yuan were available.

Since 2 yuan is as many as 5 yuan, it is regarded as 7 yuan and 5 yuan uniformly as 7 yuan. 25*7 = 175 yuan
This is 240-175 = 65 yuan less than 240,
because one 7 yuan is actually equal to one 2 yuan and one 5 yuan a total of two renminbi, so it takes the case, so it takes the two yuan, so it takes a total A 7 yuan is replaced with 2 pieces and 10 yuan, so if you change it once, you will be 20-7 = 13 yuan

for a total of 65 yuan, then change 65/13 = 5 times
After 5 times, there are 20 7 yuan, which are 20 yuan and 20 5 yuan, and the rest are 10 yuan 50-20-20 = 10 sheets

50-20-20 = 10 photos

Assuming that 50 pieces are all 10 yuan, there should be
10 × 50 = 500 yuan
more than actual
500-240 = 260 yuan
1 10 yuan than 2 yuan than 2 yuan. More
10-2 = 8 yuan
more 5 yuan more
10-5 = 5 yuan
so each type of
2 yuan and 5 yuan is
N260 ÷ (8 5) = 20 pieces of
10 yuan are
50-20 × 2 = 10 pieces of 2 yuan and 5 yuan are all X, and the number of 10 yuan is (50-2x ) Zhang
2x 5x 10 × (50-2x) = 240
7x 500-20x = 240
500 = 240 20x-7x
13x = 500-240
13x = 260
x = 20
So 10 yuan is: 50-20 × 2 = 10 photos