So we need to find a number that has the same ratio to 64 as 3 has to four. We do this by diving 64 into 4:(this is 16): so the two ratios are different by 16. To find the remaining number we multiply 3 by 16: this is 48. So 48 has the same ratio to 64 as 3 has to 4.
And 48 is the answer!
