I knew that 6 bigger than 50 is 56 and if the number is multiplied by 7 then you just do 56 divided by 7 and you get 8. So the number is 8 hope this helps :))
Let's use a for number of days when he shot 50 shots and b for number of days when he shot 100 shots. We have: a + b = 20
We also know that he shot total of 1250 shots: 50a + 100 b = 1250
We have two equations. We can solve them for a and b. Let's rearange first equation for a: a= 20 - b We insert this into second equation: 50 * (20 - b ) + 100b = 1250 1000 - 50b + 100b = 1250 50b = 250 b = 5 a = 20 - 5 a = 15
