Monu is thrice as old as Sonu’s age. If sonu age is $x$ years, what is Monu’s age?

In a $2-$digit number, the digit at the tens place is double the digit at the ones place. If the digit at the ones place is $x,$ what is the digit at the tens place?

Write the corresponding number for $400000000+200000+5000+10+7$.

Express the prime number $61$ as the sum of three prime numbers.

Show that the following pairs are co-prime: $59, 63$.

Write the smallest natural number and the smallest whole number. Are they the same?

Write the decimal fraction $35.007$ in expanded form.