If a + b = 10 and 3a + 2b = 40, then (3a + b) will be _____?

None of these

Given equations:

a + b = 10 ... (1)

3a + 2b = 40 ... (2)

We need to find 3a + b.

Multiply equation (1) by 2:

2a + 2b = 20 ... (3)

Subtract equation (3) from equation (2):

(3a + 2b) - (2a + 2b) = 40 - 20

a = 20

Now, find b:

a + b = 10

20 + b = 10

b = -10

Calculate 3a + b:

3a + b = 3(20) + (-10)

= 60 - 10

= 50