Answer:
27
step by step explanation
from the explanation,
let the number of maths that can be solved in 42 minutes = X
16 maths--------------25minutes
x maths --------------42 minutes
cross multiplying
X×25= 16×42
dividing bothsides by 25
25X/25 = 16×42/25
X = 672/25
X = 26.88 = 27 (approximately)
therefore 27 problems can be solved in 42 minutes