How do i do these without a calculator

Step-by-step explanation:

ok just try to figure out the square root if their no certain number you can do an estimate.

For example 625 squared root is 125

For higher one you can use prime factorization to get the prime factors and with that you have to make groups of numbers with the number left side

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.